My biggest issue is synchronizing with the client. You make a perfect schedule with the right set of milestones that works for you and your other projects, but

My biggest issue is synchronizing with the client. You make a perfect schedule with the right set of milestones that works for you and your other projects, but you have to be ready to answer the phone and break your flow to attend a client that is really excited because they got a whole bunch of assets for the site and they'd like to see them live :). So you have to ready to push your calendar and move people around.