Basic Requirements
• Can grind
• Can grab
• Can spin
(in that order)
• Have brain
• Are human (recommended, but not absolutely necessary)
Doing The 900
You could probably do this on all the maps, (except mega ramp obviously) but I would recommend the Orange Double Bowl (as I call it).
1. Go to the Orange Double Bowl (third map)
2. Get speed (do this however you see fit, just go pretty fast)
3. Grind over the entry way to the triangle bowl
4. Immediately turn right, grab, and spin
Make sure you get enough speed into the grind, the angle at which you approach the grind is the most difficult part of this to get right! 
This may take a few tries at most, but this is the easiest way I’ve found to do a 900 in The Ramp.
A video made by yours truly, showcasing the method.
Doing The 1080
You can only do this on the Pool map as far as I know.
Steps To Do The 1080
1. Go to the Pool (second map)
2. Get speed (do this however you see fit, just go pretty fast)
3. Go over to the deep end of you pool
4. Immediately turn right, grab, and spin
Make sure you get air going off the little hip / corner, the angle at which you approach the it is the most difficult part of this to get right!
This may take a few tries at most, but this is the easiest way I’ve found to do a 1080 in The Ramp.
A video made by yours truly, showcasing the method.