What's your risk percentage per trade relative to your total account balance?

% 1 per trade ...

Only trade EURUSD,

25 pip stop with 1:4 leverage.

About the 25 pips stop ... I thought I should also point out that ... I'm a day trader and never carry any position overnight.

Risk depends on your initial stop loss, lot size, and the value of the symbol. It does not depend on margin or leverage. No SL means you have infinite risk (on leveraged symbols). Never risk more than a small percentage of your trading funds, certainly less than 2% per trade, 6% account total.

1. You place the stop where it needs to be — where the reason for the trade is no longer valid. E.g. trading a support bounce, the stop goes below the support. Then you compute your lot size.

2. AccountBalance * percent/100 = RISK = OrderLots * (|OrderOpenPrice - OrderStopLoss| * DeltaPerLot + CommissionPerLot) (Note OOP-OSL includes the spread, and DeltaPerLot is usually around $10/PIP, but it takes account of the exchange rates of the pair vs. your account currency.)

3. Do NOT use TickValue by itself - DeltaPerLot and verify that MODE_TICKVALUE is returning a value in your deposit currency, as promised by the documentation, or whether it is returning a value in the instrument's base currency.
             MODE_TICKVALUE is not reliable on non-fx instruments with many brokers - MQL4 programming forum (2017)
             Is there an universal solution for Tick value? - Currency Pairs - General - MQL5 programming forum (2018)
             Lot value calculation off by a factor of 100 - MQL5 programming forum (2019)

4. You must normalize lots properly and check against min and max.

5. You must also check Free Margin to avoid stop out

6. For MT5, see 'Money Fixed Risk' - MQL5 Code Base (2017)

Most pairs are worth about $10 per PIP. A $5 risk with a (very small) 5 PIP SL is $5/$10/5 or 0.1 Lots maximum.

Thanks William for sharing a different approach with us ...

Thanks a lot William, I will apply this 2% and 6% from now on. Will check all of the links you provided, thanks!

I use 0.25% on a trade after a loss. Next trade I use 25% of the profits of my last trade, if I had one, for the risk. I keep doing this until my average win/loss ratio is filled or I have a loss.

You should only take into consideration YOUR risk appetite. If I risk 3% on a $100k account and I'm fine with it, that may be because I'm very experienced, or very wealthy and I'm fine losing big sums of money. But that doesn't mean it's the correct way. Find your max drawdown you're ready to endure, your risk appetite, and reverse engineer to find the appropriate risk per trade. Also, consider with your strategy what's the biggest losing streak you can get into.

It really depends on how you want to play. For example, I play without a stop loss with only DCA, i.e. i risk 100% of my capital all the time

3% is moderately risky in my opinion. I usually risk only about 1-2% per trade. Especially if you're day trading, that 3% ammount is certainly going to challenge your psychology if you're having bad months and long drawdown.