Replying to Help with mutes & rails.

Hey guys this is my first year of park. I can go a blunt grab, butters (Tail & Nose), and 180s. I was really wanting to learn how to grind a rail and do a mute. Would you guys be willing to give me some tips on how to approach the jump (as well as popping off.. i'm sorry for this one, but bear with me), Initiate the trick, and land.

*When I hit a jump then in mid-air, I dont have my weight centered.
*When I approach a rail, I end up sliding out and hitting my ass...

THANKS GUYS! I REALLY APPRECIATE THE HELP!