This works when both adding and subtracting stuff around you. If you struggle with weight loss, keeping lots of very tasty, calorically dense foods in your home is inviting you to overeat(You won’t realize it, and if you do realize, you’ll underestimate how much of the food you’ve eaten.) So you get rid of them. Or only buy a very limited amount, and be very mindful of how much you consume. You can also do something positive to remind yourself what you’d like to do more of. Keeping fruit nearby and within sight is an easy example. Prepping your meals on 1 day of the week is another. Small environmental changes can make beginning(and thus gaining momentum) much easier.