That is a difficult question to answer.
Probably, everybody does that differently.
And many people do it differently each time.
You can have sex and be almost completely dressed.
Then you just touch each other under your clothes.
Perhaps the pants are undone.
Perhaps the skirt or dress is pushed up.
You can also undress each other for sex.
First the tops, then the bottoms.
Or the other way round.
Or you can caress one another first and then you both get undressed.
You could go to the bathroom one after the other and get undressed by yourselves.
Everybody has their own way they like to do this.
It is important that you feel good about it.
It is important that you know your needs and pay attention to them.
So be very aware of what you need at that moment.
Tell the other person what you want.
If you don’t want to take something off:
It is OK to say it.