You need to work on that postflop aggression!

Hand #1: I won't comment on the preflop play; although I prefer to raise preflop, some people have made a winning strategy of playing JJ for a set in Party's $25 NL ring. Raise up the flop to something like $6 after dallasdoug's $2 bet.

Hand #2: I'd probably go for a 2/3 pot bet on the turn and fold to a big raise.

Hand #3: I'd probably open for something like $1.50 on the flop, maybe a tad more.

Hope this helps.