The bet sizing OTR is very dependent on the ranges that get there so this is a very situation dependent thing.
The sizing will be based on the bluff to value ratio of your betting range. This is a fundamental thing that you'd be better off learning from a coach/video than from a forum comment but basically you'll want to force your opponent to have a 0EV call.
Lets say the pot size is 5, you bet another 5. Pot is now 10 and villain has to call 5 so he needs to win 1/3 of the time to breakeven. That means you will need to be bluffing 1/3 of the time so you'll need to value bet 2/3 of the time, therefore have twice has many value combos as bluffs. Basically the % of your betting range that should be bluffs is the pot odds that your bet gives your opponent.

This is a really basic simplification of river play, don't take it as gospel of any kind, you'll want to learn more about strategy in general to know what sizing to use on each street, RIO has great courses and videos if you want to do that.

Usually when IP one the river you should never bet smaller than about 50% pot. The exception is if you are betting all-in.
Also if players are overcalling (which I doubt is true) then you can exploit them. So dont complain about it, just exploit them... or would you rather they were playing gto?

Hand History driven straight to this forum with DriveHUD Poker HUD and Database Software - http://drivehud.com

NL Holdem 0.05(BB)
CO ($9.37) [VPIP: 0% | PFR: 0% | AGG: 0% | Hands: 1]
HERO ($7.45) [VPIP: 23.3% | PFR: 16.3% | AGG: 32.3% | Flop Agg: 35.2% | Turn Agg: 36.7% | River Agg: 18.1% | 3-Bet: 6.1% | 4-Bet: 9.1% | Hands: 3175]
SB ($4.85) [VPIP: 0% | PFR: 0% | AGG: 0% | Hands: 1]
BB ($4.17) [VPIP: 100% | PFR: 100% | AGG: 33.3% | Flop Agg: 100% | Turn Agg: 0% | River Agg: 0% | 3-Bet: 100% | Fold to 3-Bet: 0% | 4-Bet: 0% | Hands: 1]
UTG ($4.60) [VPIP: 0% | PFR: 0% | AGG: 0% | Hands: 1]
HJ ($6.15) [VPIP: 0% | PFR: 0% | AGG: 0% | Hands: 1]

Dealt to Hero: 5h 6h

UTG Folds, HJ Folds, CO Folds, HERO Raises To $0.15, SB Folds, BB Raises To $0.47, HERO Calls $0.32

Hero SPR on Flop: [3.85 effective]
Flop ($0.96): 3h Jd 9h
BB Bets $0.46 (Rem. Stack: $3.24), HERO Calls $0.46 (Rem. Stack: $6.52)

Turn ($1.88): 3h Jd 9h 4s
BB Checks, HERO Checks

River ($1.88): 3h Jd 9h 4s Jc
BB Checks, HERO Bets $0.50 (Rem. Stack: $6.02), BB Calls $0.50 (Rem. Stack: $2.74)

BB shows: Ad Kc

BB wins: $2.74

Just wanna say this HH so cluttered hurts my eyes haha

anyways this is a standard preflop call according to GTO on flop
you can call but as soon as he checks he has not got AA KK QQ or Jx to me he would carry on betting all these its 5nl nobody playing fancy in 3bet pots your mistake for me is not barrelling the turn you have QTs villian isnt likely to 3bet QTs or QTo just call you also have Jx KJs QJs AJs though you can 4bet these hands at some frequency as a bluff if I were going to bluff I would attack his check and just barrel off and rather overbet or shove river soon as he checks he has capped his range to AK may AQ at best TT

Sure we have played together on Stars btw

GL at the tables
Stoic

You mainly want to use large river bets, But its board and situation dependent.
If you go bet bet bet line for example, your range is Pretty polarized, so i use mostly overbets and 66/75% bets mixing between those sizings. The smaller of the two sizings will include more thinner value hands like TPGK and the overbet is built More around very strong hands, and air ofcourse :)

I noticed you have some preflop leaks, go check pokersnowie, They have free solid ranges. That will boost your winrate right away

VS really good players bet sizing starts with how thinly you are going to bet for value. I ask myself, what is the weakest hand I'm betting for value? The answer to that isn't always easy. It requires that you are aware of each player's range enough to know the hands you would be targeting OTR for value. Then decide the size that will accomplish that and bluff with the right frequency. If people are calling too many bluff-catchers, you value bet more and bluff less.

VS most players, if you can stack your assumptions in a realistic way and have some idea of their range and how they might respond to different sizes, you just choose the size that is going to elicit the highest amount of overfolding, exploitatively, unless you give them enough credit to figure out what you're doing and pull the trigger on that read.

If you're triple barreling 60-75% pot OTR and getting called by Ace high it's likely that you should just stop bluffing and value bet more thinly.

BigDickPlaya
Too tight rfi and 3betting ranges. The snowie ranges are nice and free

you got no business trying to bluff people when they are overcalling, just value bet big and overbet for value