Brags. Beats. Battlestar Galactica.

Something I've noticed at 100 PLO is a lot of players can't thin value-bet very well. By this I mean either they miss out a value bet on the river or they size their non-nut hand value bets differently from their nut value bets/bluffs. I think a lot of people deciding whether to call a river bet are aware of this as well, which in fact leads to a pot sized bet probably inducing more calls than smaller bets in specific spots. These spots are where the bettor is seemingly repping only the nuts or near nuts with a big bet, and a lot of people adjust accordingly by making light (but good) calls, such as AA on a three flush king-high paired board.
The obvious counter to this is to start value-betting a lot more, which people probably realise, but it's important to not give away any bet-sizing tells such as betting half-pot with a weaker hand to eek out value, as people will probably call big bets anyway and it just makes your range when you bet big more polarised (and air-heavy if you are bluffing a lot.)
Here's are a few example hands:
 

Poker Stars $0.50/$1 Pot Limit Omaha Hi $0.20 Ante - 5 players - View hand 1029450
DeucesCracked Poker Videos Hand History Converter

BB: $367.55
UTG: $265.85
CO: $344.30
Hero (BTN): $260.00
SB: $72.25

Pre Flop: ($2.50) Hero is BTN with 8 K 6 5
UTG calls $1, 1 fold, Hero raises to $5.50, 2 folds, UTG calls $4.50

Flop: ($13.50) 9 T A(2 players)
UTG checks, Hero bets $10, UTG calls $10

Turn: ($33.50) 7(2 players)
UTG checks, Hero bets $27, UTG calls $27

River: ($87.50) 7(2 players)
UTG checks, Hero bets $85.50, UTG calls $85.50

Final Pot: $258.50
UTG mucks T A 8 Q
Hero shows 8 K 6 5 (a straight, Six to Ten)
Hero wins $256.50
(Rake: $2.00)

I think a lot of players will just show down here with 86, thinking they will only get called by better. I did think about just checking back and winning the pot or saving money versus some kind of fullhouse, but I decided there were not enough hands beating me. He would have to play pot-control with J8 (possible but very unlikely), or a set on the flop (again possible, but not that many combos), or have some kind of weird two-pair with the 7 (again possible) in order to have a winning hand. On the other hand, I still see him having a lot of ATs and A9s here, as well as some AK hands which may very well hero call.

Going with what I said earlier, I decided to full pot it. The main reason this is good is because no one would expect you to full pot anything but a big fullhouse here and it looks very suspicious for me to want to bet turn and also value bet big on the river. Villain probably would think "if he had J8, he would bet smaller or check back because there's little value, he is pretty much repping only AA/TT" and hero call a lot lighter than a smaller bet.

Of course, it's important not to overdo this or (good) opponents will sandbag you on the river more with their strong hands, as well as bluffs using blockers. It's a purely exploitative play betting 86 here, based on the current metagame of river play at low stakes PLO.

Here's another:

Poker Stars $0.50/$1 Pot Limit Omaha Hi $0.20 Ante - 6 players - View hand 1030163
DeucesCracked Poker Videos Hand History Converter

SB: $142.10
BB: $150.15
UTG: $76.25
MP: $345.40
CO: $407.40
Hero (BTN): $594.20

Pre Flop: ($2.70) Hero is BTN with 5 4 3 8
1 fold, MP calls $1, 1 fold, Hero raises to $5.70, SB calls $5.20, 1 fold, MP calls $4.70

Flop: ($19.30) 8 7 Q(3 players)
SB checks, MP checks, Hero checks

Turn: ($19.30) 3(3 players)
SB checks, MP bets $18.35, Hero calls $18.35, SB folds

River: ($56.00) 6(2 players)
MP checks, Hero bets $53.25, MP calls $53.25

Final Pot: $162.50
MP mucks T A Q 7
Hero shows 5 4 3 8 (a straight, Four to Eight)
Hero wins $159.50
(Rake: $3.00)

Villain almost never has a better straight here, because he'd be value betting most of those himself. Given the pot-sized turn lead and the river snap-check, I expect him to have a set or two pair often. Again, when I pot this it looks like I only have T9/bluffs, so might as well pot it with a few more value combos.

Here's a spot where villain is repping way too thin: 

Poker Stars $1/$2 Pot Limit Omaha Hi - 5 players - View hand 1030165
DeucesCracked Poker Videos Hand History Converter

Hero (CO): $247.80
BTN: $250.40
SB: $139.60
BB: $197.00
UTG: $213.60

Pre Flop: ($3.00) Hero is CO with 2 9 9 4
1 fold, Hero raises to $7, 2 folds, BB raises to $22, Hero calls $15

Flop: ($45.00) 5 8 A(2 players)
BB checks, Hero checks

Turn: ($45.00) Q(2 players)
BB bets $30, Hero calls $30

River: ($105.00) 8(2 players)
BB bets $103, Hero calls $103

Final Pot: $311.00
Hero shows 2 9 9 4 (a flush, Ace high)
BB shows Q 6 A J (two pair, Aces and Queens)
Hero wins $309.00
(Rake: $2.00)

He is pretty much only repping AA when he snap pots the river, probably under the logic that I never have a strong hand myself and because he 3-bet he can have AA. However, AA makes little sense after checking the flop, unless he was planning a check-raise on this board (which is unlikely though not impossible.) This would be a perfect spot to pot a nut flush and even a J-high flush for thin value, but people rarely will and instead, they will tank a bit, and bet something like 2/3rds pot.