There is a large military base near my parents farm and you can always tell when they are out in the field because I would have to go restretch the top wire, its pretty easy to just puch down on the top wire and cross over.
To do the least damage, follow the fence to a corner or gate and if you can't climp the gate there should be a diagonal brace at the post or the corner post, you can step up over the fence using that brace without stretching the wire.