Small stakes? yes! to be appropriate! I think it is!

I make a small bet

I would check in most cases

I usually bet it out, but I guess if you will only get called by a pair then its better to check coz you`ll only make your flush 1 in 3 times by the river

Bet it out

You should raise if:

1) your draw is so strong that you don`t mind getting reraised and going all-in
2) you think you have a lot of fold equity

if this is not the case, you should generally just call.

Nice explanation. I always wonder whether I should call or raise the flop with a FD, any advice on that?

well you`ll hit the flush about 1 in 5 times, so lets say the pot is $12, and you opponent bets 2/3 of the pot, $8, so you`re getting 1 to 2.5 on your call. You`re not getting the expressed odds to call, so you need to make up for that in implied odds. In this case you need to win another $12 on later streets to make up, since you need to win $32 in total when you hit and the pot is only $20 on the flop. After you call the flop, the pot is $28. If he has an A, he is likely to either bet or call the turn for 2/3 pot, so you can expect to make about another $20, and sometimes you might get a riverbet out of him as well, if he has AK or a set. So far it looks good, but you`ll also sometimes stack off to a higher flush or a FH, which reduces you`re implied odds significantly.

On A high boards where the A is of the flush color, he is way more likely to hold an A than a FD though, since there are only a few FD combinations that he would raise preflop, lets say T9s+/KJs/QTs, thats 6 combinations, but there are a ton of A combos, AK 9, AQ 12, AJ 12 AT 12 etc.

You call a small raise with 78 diomonds and the flop comes 2 diomonds Ace of Diomonds K ing of clubs

How much can we call with only a flush draw without being a fish. All we have is the flush draw.