I've gone it alone (4 stone down so far).
For me, this has meant using this time to really and truly understand myself and my body. As pp have said, there are all sorts of things that 'mess' with the cals in/cals out balance. Those things vary by individual.
I've made it a goal to try and work out what varieties apply for me, specifically.
I count the calories I eat, but typically try not to eat things I wouldn't eat anyway. I might eat less of some things and more of others but try not to eat things I would never previously eat or totally cut out things I love.
e.g. a close friend of mine always starts a diet with an advocado smoothie. That's what she thinks is required. However, she hates advocados and never usually drinks smoothies - so it's just not right for her. She can never keep it up over a long time.
I hate advocados too. So I ain't gonna eat them. I love ice cream so I am never going to give it up, though might cut down on how much I eat. I like veg so can eat a bit more of that and enjoy it.
I track my TDEE, track my weight, track my calories and use all that data - over a sustained period - to work out the truth for me.
e.g. If, over a 4 week period, I eat an average of 1800 calories a day and Fitbit shows I burn an average of 2800 calories a day and I lose about 7lbs in that time. Then I can use that to work out that I need a deficit of 4285 calories to lose a lb - regardless of whatever 'the books' say about it being 3500 kcals.
I can see that just before a period I weight about 4lbs more than I do just after - so I learn to discount those weigh-ins because they are out of line.
If I spend enough time and patience thinking about the things that affect how I feel I can spot how I eat a whole lot more if I am tired or cold. So I need to do everything I can to ensure I don't get tired and I don't get cold. If it happens anyway and I have a day when I am very tired I might deliberately eat my whole TDEE calories and not worry about it. I give myself permission to do so, and it becomes less like a cheat and more like deliberate self care to feed myself the calories I need when I most need them.
I can spot that 3 weeks is about the length of time before, despite all my mitigations, a diet feels relentless. So I can deliberately have 1 week of eating my TDEE every 3 weeks of eating at a deficit. I can tweak the timing so fit with my plans - so my next TDEE week with include Easter and this will allow me to eat a big old Easter Egg and know it is not harming me.
I worked hard on coming to terms with this being a loooong term deal. If I lose an average of half a pound a week then I am winning. And tracking all my weight allows me to see that 'half a pound a week' might not look like that on the scales. It might look like 3 weeks of staying at exactly the same weight and then one week of 2lb loss.
This is a lifetime deal. So don't think "what's the most effort I can put into losing weight". Think "what's the least effort required to start the scale shifting in the downward direction that I can live with forever".