I’d say use the least amount of leverage but again it all depends on how many units you’ll be trading and if your style is one that consist of holding multiple positions.
Just use the least amount & stick to how much percentage you’re willing to risk per trade.
For example if you are risking 1% on $900 your risking $9 per trade. (Let’s say you have 100:1 leverage)
Let’s say your strategy incorporates the volatility of a market lets pick a pair like USD/CAD for sake of explaining.
You see amongst this pair it swings 40-80 pips in a day and your looking to get to get at least 10 pip profit.
Well you have options here. You can either reduce the amount of units so you can have a widened SL/TP or you can choose to use more units and have a tighter SL/TP gap (since we are only willing to lose 1% per trade). Now the most important thing is to factor a pairs volatility if you are going to use a tight SL/TP lets say maybe 10,000 units it’s about 0.73/per pip (at 10 pips it’s worth $7.33 but again that SL is just as tight because of the amount of units 10TP/10SL), but for example at 2500 units it’s about 0.18/per pip (at 40 pips it’s worth $7.33 and vice versa with the SL but as you can see you have way more space incase the pair reverses (40TP/40SL).
I hope that is clear - I tried to explain easily.