400m and 200m tips?

I plan on breaking records next year and I need some advice on sprint mechanics, starting off the block, and etc.

Well for 1, starting off the block, it is all on preference and what make you comfortable. Just know which leg is your lead leg and have that leg towards the front. Next keep your hands slight behind the lines so you do not get dq'd. Have patience and do not become overly anxious to where you move before the gun shoots.

On M/W, warm up with n 800 meter run then practice your initial burst by running 20 sets of 50 meter runs with 30 second breaks in between with a warm down 800m. T/TH, lift weights and practice how you want to come out of the blocks once done with lifting. Fri/Sat run a 1 mile warm up, then do 6 400 meters with a 1 minute break; warm down with a mile run. On sunday, take a break, then repeat the process.