As a slave in training, I start doubting my worth when I don't get a response within an hour.
From your brief question, I am going to assume that the response you are waiting for is through text, so this could be a long distance or online only relationship. I am going to respond as if this is the case.
Here's your answer in short: you continue to do what you would be doing without him. You live, make dinner, do chores, go out with friends, work and everything else you enjoy doing. Sitting around and waiting for a response that may or may not come, is time wasted. Your partner could be busy, doing life things on his own and not there to wait hand and foot on your messages. While I understand that it's nice to get responses in a timely manner, there are times when this just isn't possible.
Now, if you can't do what you want to do without his okay, then you don't get to do it until he responds, so have something else to do. If you have to ask permission to go to the bathroom, however, I would get a backup plan in place; say, for example, you have to wait 5 mins but if you don't get a response before that you can go.
And if you are often waiting for responses and you desire more attention or communication than he is giving you perhaps it is time you have a heart to heart with him about your expectations for him as your Dominant. If he's not willing to give you what you need (more communication) then it's a compatibility issue that you either have to work around or seek someone else that can give you what he can't.