Know what you’re doing.
Have it under control.
If you want to do it this way, you can.
If you want to do it that way, you can.
Or to put it another way:
If I say, ‘do it this way’, be able to do that.
If I say, ‘now do it that way’, be able to do that, too.
Having it under control means that you don’t have to be concerned with the technique, you can just get on with making music that sounds good.