It's better to set SL first. Then entry.
Rather than Entry then to set abritrary SL.
Usually based on a dollar amount kind of stuff.
I'd advise to loosen the SL if too tight.
Because Losses can add up quickly,
Even if your idea turns profitable.
Eliminate the false negatives.
To be taken out on winners.
Size's more important than price.
But often we prefer to add contracts,
Rather than to increase,widen, the SL.
After it depends ...
What's your Expenctency ?
With a tighter or a wider stop loss ?
I'd personally go for less leverage,
But a wider stop loss. For less False Negatives.
Which is to lose money on a trade that's actually not bad.
To let room for noise from Algos and scalpers to be harmless.
Some take volatility into consideration,
They say tight / loose SL when non volatile / volatile.
Depends ... It's conditional on volatility, entry, expectations.
But not on a dollar amount or other arbitrary, abstracted, parameters.
But always have a predefined exit point.
And STICK TO YOUR PLAN.
PS: One Key Word here is OPTIONALITY
With wide SL you still have the choice to get out tight.
Where on tight ones, you're taken out, even if still convinced.
Plus with wide SL. It can gives you an opportunity to break even.