I use the most standard one: My S/L is certain percentage of my balance (I use 0,35% for one account and 1,5% for another), and I have always fixed T/P which is S/L*3. So profit/loss ratio is 3:1. NO EXCEPTIONS!!!
Anton, did you ever consider statistics? With having profit/loss ratio 3:1 you would get, in a period of time, let's say, 10 small losses and 1-3 profitable trades, only because the market will hit first the closest point to it (in our case this is SL), isn't it?
That means at the best we will have a break even (b/e) situation in money, but w/l ratio will be ~30/70%, correct?
Ironically, exactly the same is true for opposite combination 1:3 you will be break even in money, but w/l ratio will be 70/30%. 😄
So, if your point is to increase trading probability try to use opposite ratio for TP vs SL (1:3). By this way you would get lots of small winnings and only a few big losses wiping out all your profit. But w/l ratio will be very nice (~70/30%)!
So, as you can see, the Risk Management is something different and is not so simple as 3:1 or 1.5:1 ...