You probably already do them but are you doing them correctly? It is important to perform exercises properly or they will not be effective.

Keep your knees behind your toes.

Keep your chest tall

Keep your shoulders below your ears

Keep your abs in tight

Start with 2 sets of 8 if you are a beginner.  3 sets of 8 if you are more advanced.

Here are 3 modifications:

Chair squats:

                                                                                                                                              Ball squats

                                                              Start with legs extended then squat.

                                                                             Knees are taken to a 90 degree angle.

standing squats with weights.