Oh boy, where should I begin? I guess I'll just start with the tracks I'm more proud of 
Daisy's Garden:
How could Daisy NOT have a garden track? So here's Daisy's Garden, set to be played in the Flower Cup. The garden is meant to be something like a public garden. So as we enter the garden, we see giant hedges shaped after the MKW Daisy Circuit statues. Then the path splits left to the Flower Cannon or right through a broken part of the wall. We then reach Daisy's private gardens, including her greenhouse, which is guarded by a Chain Chomp. Piranha Plants also keep the flowerbeds "safe."
Birdo Circuit:
Birdo has always been one of my favourite characters, and I felt that since she's a main character it seems weird for her to not have a racecourse for herself. So here is her first track, based upon the lands of Subcon! You start in the typical SMB2 hills and go through a Subcon door where the path splits; you can take the lower desert path where Pokeys roam, or you can take the higher up, but slippery, ice path where Flurries can be found running around. Eventually the paths merge towards a cloudy area, which is actually Wart's castle! Wart can be seen sitting on his throne, and he blows bubbles that explode when they near a racer. Again, the path splits between left and right; the left path is shorter and goes through a Warp Pipe, but it lacks Item Boxes; the right path is longer but has the usual Item Boxes. As well, the whole castle is infested with Shy Guys and pellet-shooting Snifits. The path continues along a dirt road, becoming snow, then back to dirt, where it reaches an N64 Yoshi Valley-reminiscent area, with giant rolling Birdo eggs, before reaching a crooked road where Robirdo shoots eggs down. The final stretch of the track is a climb back up the grassy mountains.
Chomp Country:
Due to the abundance of Chain Chomps appearing in the series, this track was created. This is like a "nature reserve" for Chain Chomps, and the track is shaped like a Chain Chomp. Roaming the track are the Chain Chomps from DS Peach Gardens with the Item Boxes trailing behind them. Close to the island are the GCN Luigi Circuit Chain Chomps, ready to bite those who get too close. Along certain parts of the track are the rolling Chomps, like from Wii Chain Chomp Roulette, that roll along the certain parts of the track. The "eye" of the Chain Chomp island is represented by a small pond, and it is from the depths of this pond that the homing Silver Chomp rises from. Confined to a certain area, it will home in on the racers and try to make them spin out. The inside of the island is jungle, and Lakitu will have to rescue whoever tries to drive through it.
DK's Jungle Safari:
This track is sort of like a collection of all past DK jungle courses, except for the most recent DK Jungle from MK7, since the track was made before MK7 came out. The track starts out in an area very similar to GCN DK Mountain, complete witht he Barrel Cannon and the volcano. As you travel down the mountain, you reach a sort of rapids river area, which was inspired by the DK's Jungle Tour custom track for MKW. The path then reaches a jungly area and enters a cave area similar to N64 DK's Jungle Parkway, before crossing a suspension bridge and entering a jungle area. You then go on a ramp and onto the cruise boat from the N64 course, and after you jump off it you reach a windy jungle area before going up DK's Treehouse and down its slide back to the finish. The course also has many well-hidden shortcuts.
By the way, if you're wondering why there are no Glider or Underwater segments in these courses, it's because I made these courses before Mario Kart 7's gliding and underwater gameplay elements were announced, and as well, I'd planned for these courses to be in a Mario Kart game more similar to Mario Kart Wii than Mario Kart 7.
Daisy's Garden:
How could Daisy NOT have a garden track? So here's Daisy's Garden, set to be played in the Flower Cup. The garden is meant to be something like a public garden. So as we enter the garden, we see giant hedges shaped after the MKW Daisy Circuit statues. Then the path splits left to the Flower Cannon or right through a broken part of the wall. We then reach Daisy's private gardens, including her greenhouse, which is guarded by a Chain Chomp. Piranha Plants also keep the flowerbeds "safe."
Birdo Circuit:
Birdo has always been one of my favourite characters, and I felt that since she's a main character it seems weird for her to not have a racecourse for herself. So here is her first track, based upon the lands of Subcon! You start in the typical SMB2 hills and go through a Subcon door where the path splits; you can take the lower desert path where Pokeys roam, or you can take the higher up, but slippery, ice path where Flurries can be found running around. Eventually the paths merge towards a cloudy area, which is actually Wart's castle! Wart can be seen sitting on his throne, and he blows bubbles that explode when they near a racer. Again, the path splits between left and right; the left path is shorter and goes through a Warp Pipe, but it lacks Item Boxes; the right path is longer but has the usual Item Boxes. As well, the whole castle is infested with Shy Guys and pellet-shooting Snifits. The path continues along a dirt road, becoming snow, then back to dirt, where it reaches an N64 Yoshi Valley-reminiscent area, with giant rolling Birdo eggs, before reaching a crooked road where Robirdo shoots eggs down. The final stretch of the track is a climb back up the grassy mountains.
Chomp Country:
Due to the abundance of Chain Chomps appearing in the series, this track was created. This is like a "nature reserve" for Chain Chomps, and the track is shaped like a Chain Chomp. Roaming the track are the Chain Chomps from DS Peach Gardens with the Item Boxes trailing behind them. Close to the island are the GCN Luigi Circuit Chain Chomps, ready to bite those who get too close. Along certain parts of the track are the rolling Chomps, like from Wii Chain Chomp Roulette, that roll along the certain parts of the track. The "eye" of the Chain Chomp island is represented by a small pond, and it is from the depths of this pond that the homing Silver Chomp rises from. Confined to a certain area, it will home in on the racers and try to make them spin out. The inside of the island is jungle, and Lakitu will have to rescue whoever tries to drive through it.
DK's Jungle Safari:
This track is sort of like a collection of all past DK jungle courses, except for the most recent DK Jungle from MK7, since the track was made before MK7 came out. The track starts out in an area very similar to GCN DK Mountain, complete witht he Barrel Cannon and the volcano. As you travel down the mountain, you reach a sort of rapids river area, which was inspired by the DK's Jungle Tour custom track for MKW. The path then reaches a jungly area and enters a cave area similar to N64 DK's Jungle Parkway, before crossing a suspension bridge and entering a jungle area. You then go on a ramp and onto the cruise boat from the N64 course, and after you jump off it you reach a windy jungle area before going up DK's Treehouse and down its slide back to the finish. The course also has many well-hidden shortcuts.
By the way, if you're wondering why there are no Glider or Underwater segments in these courses, it's because I made these courses before Mario Kart 7's gliding and underwater gameplay elements were announced, and as well, I'd planned for these courses to be in a Mario Kart game more similar to Mario Kart Wii than Mario Kart 7.