Something I started doing recently is every time I go to the restroom I do 25 normal squats and 25 sumo squats, that combined with drinking 65-130 ounces of water a day means that you will be doing a TON of squats! When you have done that for a week increase it to 30 30 and keep going up 5 until you want to, but one thing to keep in mind is that if you go to far then it will take a while before you get out of the bathroom, so you could just keep track of how many bathroom trips and then complete your squats before bed or something. Also if you want to while you are in the shower washing your hair or whatever do 50 normal and 50 sumo squats and if you take long showers like me then do heel raises too!