I've found that Bisquick can make a pretty dry biscuit. 2 things that will help counteract this natural tendency... 1. Don't over-mix the dough. Mix the ingredients just 'til they're mixed and everything is moistened; then drop and bake. 2. You may have added too much biscuit mix; you may need to add a little bit more liquid to counteract the dry dough and get some moisture back into it.