Depends what issues you're specifically having. Here a few tips.
Identify which types of players are at your table, and adjust your strategy accordingly. For instance, when I first started playing poker I'd always have a solid set strategy for which
hands i'd play and how i'd play them preflop and postflop against all players, but of course this can't be done. If you're playing against a lose player who likes to limp a lot, don't bluff them, but instead bet for value with your stronger holdings. Middle pair can be a strong hand against a loose passive player who likes to call you down, and you can usually get two streets of value out of that particular hand depending on the board texture. Against a more tighter player however you need to make sure you're only getting involved in big pots with premium holdings.
Here's a few basic tips
- Don't call a bet just to see a turn card hoping you hit a pair.
- [against tight players and/or good players] Don't bet too much out of position postflop. Check/call or check/raise is the best play. You can always play more aggressive when in position.
- Don't bet for the sake of betting, have a reason every time you make a bet. Are you betting for value, or are you betting as a bluff? Once you figure this out surprisingly your decisions will be more easier postflop.