what am i doing wrong
 

i've been having trouble getting good casting distance. I'm using a 9' rod for plugs and a 10' rod for bait. The 9' is rated 1-5 but the sweet spot is about 3. The 10' is rated 4-8. I'm using lead in that range and still am not getting good casting distance. the reels are designed for the surf-light wieght-large core-shallow spool-tall spool-metal spool lip. im using the technique like loostening the lug nuts on a tire, pulling down hard with the left hand while punching hard withthe right. I'm using 20 pound mono. is there any thing i can do besides using braid?
Please help.

How many feet did you cast?

Drop down to 17# or 15# mono, and use a shock leader of around 50#, that should help.

What DaveS said. Also, don't bring your offering all the way up to the rod tip. Let it dangle down even to the ground. When you follow through, it'll give a good whipping action. Just make sure no one is standing right behind or next to you. Keep practicing!

Are you a beginner, jfisher?

you never specified your reel
 

baitcaster or spinning? i assume spining...i've been using spider wire with a flourocarbon leader and it casts a mile