1-1: Easy enough. Don't stress when you get to the pipe, wait until you hit the cavern floor and then run. You should still get 380. Then go up top, get a stair jump off the 3rd stair, and you will have a 370. 1-2: Once again fairly easy, only one jump to be worried about. After the opening section run under and clip past the first Koopa and hop off the two Goombas. Get a quick turnaround and then get jumps off the pipes until you reach the pipe to 4-1. 4-1: Easy if you keep running. A stair jump and two piranha pipe jumps are all. 334 is optimal. 4-2: Jump off the edge of the two blocks and land up top. Hop off the 2nd of the two Goombas and then hop and hit the vine. Hit the farthest hidden block to the right and get a couple of block clips. Get a stair jump in the warp zone and head to 8-1. 8-1: Pipe jumps as much as possible and...it's a lot to explain. Just aim yourself to try and hit as few enemies as possible while still keeping top speed and you will easily get over 275. 8-2: Hop onto the third block than jump around the Koopa onto the 4th and get another jump right under the Lakitu. Grab the mushroom and keep optimal speed. 8-3: Get another power-up at some point, make sure your Previous State setting us turned on and get to 8-4 with at least a mushroom. 8-4: Get a turn around on the opening. Once you get to the final section go all out. You can lose your mushroom to the Hammer Bro. and then just run and make it to the axe. Keep the mushroom until the final section. If you Don't, then you risk about 10-20 seconds time loss.

Hope this helps!