For a while I was placing a science board on the table and this would be my family's cue that I was unavailable. That did not work for more than a few weeks
I have since started planning my sleep schedule so that I go to bed early so that I can wake up early. The morning hours at my house are some of the best times for me to study.
You can also try to study during your breaks in classes rather than going on your phone and checking your Facebook
Also try going to the local library. If you have kiddos, a fast food place with a playground is a good alternative to being at home. It gives the kids something to occupy their time rather than bugging you!