Hey @CherryBomb
Something I have found works for me is making whatever those routines are into habits as much as possible. Used to find that all the best intentions go to hell in a handbasket kind of fast unless I can develop a habit around them (so it becomes automatic). For example ...
Problem: Used to tell myself I need to eat healthier during the day, but would end up eating rubbish in the afternoon because I half starved myself all day. At the low sugar end of the day I would cave in. Willpower had disappeared.
Solution: Recognised that low sugar in afternoon was making me cave in. Recognised that I am very lazy when it comes to preparing food. So I started shopping on Monday morning for healthy food that required, minimum to no preparation.
Habit: Every Monday morning after my walk, would drop into early opening fruit market and buy my stash of stuff.
Result: Graze on healthy food throughout the day, and don't eat rubbish in the afternoon. Am also eating less at dinner.
Whether it is having someone turnup at your front door for excercise to force you to go, or putting a timer on your computer to stop you spending too much time on it, the key is placing it on automatic pilot.
A good book on this is "The Power Of Habit" by Charles Duhigg.
Also "Willpower: Rediscovering the Greatest Human Strength" by Roy F. Baumeister & John Tierney
Personally, my willpower is weak, but my habits can make me strong.