First hand at this table and I've not come across any of the players before. Micro stakes here and I've been using the 19-hand to keep me straight (low br).

Seat 1: barmaley71 ( $1.91 USD )
Seat 2: DenyGuess ( $5 USD )
Seat 3: tom_cod ( $5.88 USD )
Seat 4: Schleichi019 ( $12.05 USD )
Seat 5: Leahcim87 ( $4.98 USD )
Seat 6: cadavila ( $5.02 USD ) (Button)
Seat 7: players19 ( $4.92 USD )
Seat 9: bakal84 ( $13.62 USD )
Seat 10: Flanders_zH ( $2.95 USD )
Seat 8: PhoenixWolf8 ( $4.96 USD )

players19 posts small blind [$0.02 USD].
PhoenixWolf8 posts big blind [$0.04 USD].
** Dealing down cards **
Dealt to PhoenixWolf8 [ Qh 7h ]
bakal84 folds
Flanders_zH folds
Flanders_zH: nh
barmaley71 folds
DenyGuess folds
Flanders_zH:
tom_cod calls [$0.04 USD]
Schleichi019 folds
Leahcim87 folds
cadavila folds
players19 calls [$0.02 USD]
PhoenixWolf8 checks

** Dealing Flop ** [ 6h, 5h, 4d ]
players19 checks
PhoenixWolf8 checks
tom_cod checks

** Dealing Turn ** [ 2h ]
players19 bets [$0.20 USD]
PhoenixWolf8 raises [$0.40 USD]
tom_cod folds
players19 raises [$0.40 USD]
PhoenixWolf8 calls [$0.20 USD]

** Dealing River ** [ 8d ]
players19 bets [$1 USD]
PhoenixWolf8 calls [$1 USD]
players19 shows [ 6c, 5c ]two pairs, Sixes and Fives.
PhoenixWolf8 shows [ Qh, 7h ]a flush, Queen high.
PhoenixWolf8 wins $3.16 USD from the main pot with a flush, Queen high.

I really feel I played this too passively, I figured I was worried about the other guy having a better flush. Thinking on it, I'll say this worry has more to do with my BR not being ideal enough to lose a buy-in within the first few hands of a sitting.

What I'd like to know is when I'm in this situation, or something similar, what would be the best way of maximizing my profits?

A.