I generally will fold unless there is no bet to call. Investing in a bad hand generally gets you a negative return. If there is no bet to call in the big blind or it's an ante game, I would hold the highest ranks in the following:
- suited with a high card A♣5♣ before K♥ 6♥
- suited connectors 7⋄ 6⋄ before 4♣3♣
- suited gapped connectors 9♠7♠ before 5♥ 3♥
- unsuited connectors J⋄T♠ before 4♣3⋄
- unsuited gapped connectors T⋄8♠ before 7⋄5♠
- high cards A♠J♣
As you can see you are drawing three cards to fill a flush or straight and more likely end up with high card or a mediocre pair. Not really worth investing in in the first place.
I fold often conserving my bets while I watch my opponents throw money in the pot playing random best hand. When I do come in I have a real shot at collecting.
The reason I would hold gapped connectors is that the chance of making a pair is the same for high or low cards, so if you can also make a straight it gives you more possible hands to make.