When you hold the nuts after the river card and want to extract as much money as you can from your remaining oponent, how much should you bet in general? Half pot? Pot? Push? Any thoughts on this?

Example:
0.25/0.5$ NL 10 player
I'm dealt
:Ad::Qd:
I raise 2$ preflop and get two callers.
Flop
:Ah: (pot 8$)
He bets half pot (4$), one fold, I raise to 12$ and he calls.
Turn
(pot 32$)
He bets 6$ and I just call suspecting a set or two pair, for some reason I do not fear a flush draw here at all and I want to see that river card for my own flush draw.
River

He bets 6$ again I raise to 20$ and he calls. I win a nice pot.
........................
The question is if I could have made more from this hand Stack size was 85$ left for him and about 65$ left for me before the river card.
Read: solid player, no rock, not very loose either.