One of the best pieces of advice I can offer for building better self-control is to prepare better alternatives.
The thing to understand is that if you say to yourself, “Don’t eat the cookies” the mind doesn’t hear the “don’t”—it just hears “cookies” over and over again.
…And it’ll keep wearing away at your self-control until you cave in.
Better would be to have a solid alternative ready that you can shift your focus to when you need it, on demand. For example, rather than “not eat cookies” being the focus, eat a protein bar with peanut butter on top instead (what I do). Or if you want to control yourself from eating anything additional at all, get into a book or task asap so that your mind can shift away from the thing you’re trying to avoid.
The secret to better self-control is in the speed—the quicker you can begin an alternative, the less willpower you’ll drain and the more you’ll have for other things later.
Another example: today I took a sticky note and wrote at the top, “Instead of socials:” and underneath started a list of things I can do on-demand when I’m feeling lazy and like I want to browse mindlessly. I listed things like “RV” (to search for an upcoming trip), “Posters” (to create for MMQ), “Philly D” (a news show I watch), etc.
Which might sound silly, but is kind of what I need when I’m feeling lazy and mindless. No thinking, just look, type, and go.
Bottom line: when you’re under a spell of desire (cookies, socials, etc), easy is everything… because easy is fast… and fast is the secret.