Habit stacking is a great way to train yourself to form new habits because it makes it harder to forget about your new habit. When you are trying to get in the habit of a new behavior, one of the hardest things is to remember to do it when you should. If you are trying to get into the habit of laying out your clothes the night before, you might not think about doing so until you are in bed with the lights off. Then, you either have to drag yourself out of bed to do it or give up on the habit for the day.
Habit stacking helps eliminate this forgetfulness by tying a new habit to a preexisting one. For example, you are in the habit of charging your cell phone at night. To remind yourself to lay out your clothes, you might put your charger on top of your dresser instead of on the bathroom counter. When you go to get your charger, you see the dresser and are reminded to lay out your clothes. Overtime, it becomes habit to lay out your clothes when you go to plug in your cell phone. This same theory works with meditation as well. Leave a reminder of some kind in a place where you automatically go at a certain time every day. If you wanted to meditate in the morning, for example, you might put a sticky note on the vitamins you take every morning to remind you to meditate after you take them. If evening meditation fits your schedule better, you might leave a note next to your toothbrush so you remember to meditate once your teeth are clean. After a while, the reminder will no longer be necessary, and it will be a habit to brush your teeth and then go meditate.