Yes, sure...Suppose you are offered to play the following game. We flip a coin. If it's heads, you lose your bet. If it's tails, you win twice the amount of the bet. You can play as many times as you want.
The house sets the rule: you may not bet more than 95% of your account. Let's call it the margin rule. Now, the question is, how much should you bet on each flip of the coin? Your answer would determine your leverage.
I think maybe there's a misunderstanding here somewhere. When I talk about "margin", I am really referring to "margin requirement". To use your terminology, the house has a rule that, in order for you to participate in the game you've described, where you bet $1 for every flip of the coin, you need to put, say, $20 into an escrow account held at the exchange. This $20 is an absolute amount that has nothing to do with your account size, a priori.