(This one is for those who weigh regularly. If you don't weigh yourself, don't start. If you can stop weighing, definitely stop.)
It's not how often you weigh but what you expect and what you tell yourself that really matter. If you are successfully maintaining while eating what you want, when you're hungry, and to satisfaction. That's major! You have to be able to do that first in order to stop the yo-yo restriction weight cycle. As you practice (remember, it takes practice) noticing the subtleties of hunger and fullness and eating to satisfaction, your weight may start trending down over time, but if you're already a healthy weight it will not be a magical pound or two every week like when you're severely restricting, or like for someone who has more body fat to lose. If you expect that, it will cause anxiety and conflict. If you expect that your weight is going to stay about the same from week to week, perhaps gradually trend down over time, but occasionally bounce up for no special reason, then your expectations are more in line with reality.
The only time I have ever lost weight permanently and kept it off effortlessly, I lost it at the rate of about a pound a month. Slow is good. Slow rules, because it means the method is sustainable. We all know how to do something radical and short lived, or something obsessive and impractical. Most of us have never tried slow, sustainable, enjoyable. I sure hadn't! A week with no loss on the scale and I'd think, "Well, this isn't working." and immediately do something stupid and ineffective. It was my own expectations tripping me up. Expect something different. Give it time to play out. You'll be amazed.
When I try something different with my eating or workouts, I give it 4-6 weeks before I decide if it's working for me. It takes that long for there to be a concrete result from the change. That's if you want to see a difference in scale weight, or clothes fit, or workout performance, or muscle definition or something. My old approach was to give it a day and a half, maybe a week if I was really determined, freak completely out and change everything. Is it any wonder that nothing worked? It helps to take a much longer approach.
Hmm, to play devil's advocate though, don't you think getting on the scale for you is boring now because you've done all this work over years to get to a point where you know what to expect when you step on the scale?
Yes, good point. The "ho hum" happened as a result of two things: learning to question painful untrue thoughts (I had a million of them), and weighing myself every morning for a few years. So there was no special isolated day with everything riding on it, no week-long build up, no month of denial eating, no mystery bloating. I saw the completely predictable up down up down up down of my every day eating in every single situation until seeing it bored me to tears. I also came to accept a 10-pound range as normal maintenance. I'm generally somewhere in the middle of it, but visiting the upper or lower ends of it is still normal. Right now I weigh 6 pounds more than I did at the end of last summer but that's completely normal and predictable coming out of winter, to be a little higher up in my range. So, it's not like even when you nail the habits and the thinking, you'll weigh x pounds, The End. Sometimes you'll gain 4 pound over 9 months, or lose 4 pounds in 4 months, or gain 5 pounds overnight after a high-sodium restaurant meal. I certainly do. All the time! Those fluctuations are still within the realm of successful maintenance and not a harbinger of fat pants. They don't even affect body comp necessarily. Having more carbs/water packed into my muscles may make me look leaner than I would at a lower weight.
It's normal for there to be moods and seasons and for your body to reflect your inner experience. None of it is bad or wrong.
Personally, I avoid calling it "weigh-in day" and building it up as if it means something. It does not. I experience stepping on the scale at the same emotional level as checking the temperature outside or checking my tire pressure. They're just numbers. None of them are going to affect my mood, self-worth, or the way I eat that day. Getting on the scale has become so boring I have to put forth some effort to remember to do it at all. I find that "ho hum" mindset to be much more effective than my old "diffusing a bomb" mindset where I'd get super intense about the outcome and the ramifications. It's fascinating in hindsight how many of my food and weight problems were actually thought problems. I could manipulate food and weight variables endlessly with little to show for it, but change your thinking and everything changes.