Whats the best way to sneak to her without getting caught?

So schools out and i barely ever see my girlfriend her mom is kinda grouchy and lazy and wont let us hang out. I snook over to her house last week and everything was perfect. Her mom isnt usually home during the day. Its something we plan on having me do more often. How do i make sure there is no way to get caught? What are some precautions i take? I just want to see my girlfriend and spend time with her but if her mom came home and found me she would be mad so i want to have the lowest risk possible of getting caught and still having time to spend with my girldriend.