There was a hand ealier about betting the river, and now here's another example. I seriously thought of checking, hoping for him to bet/bluff and then decided to raise a bit and decided on 300 - less than half-pot.

Any advice on how I could have extracted more?

PokerStars No-Limit Hold'em Tourney, Big Blind is t30 (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

UTG+1 (t1320)
Hero (t3240)
MP2 (t1020)
CO (t2235)
Button (t1325)
SB (t4440)
BB (t1650)
UTG (t1510)

Preflop: Hero is MP1 with J, J.
2 folds, Hero raises to t90, MP2 calls t90, 4 folds.

Flop: (t225) A, J, 8 (2 players)
Hero bets t90, MP2 calls t90.

Turn: (t405) 4 (2 players)
Hero checks, MP2 bets t150, Hero raises to t300, MP2 calls t150.

River: (t1005) A (2 players)

I (Hero) raised 300 and villian folded (For some reason this didnt show up in converter)

Final Pot: t1005

Outcome: Hero wins t1005.