For weekend plans, I assess menus before hand and will happily skip other meals in the day if I know I am going to have a big dinner out.
I try to avoid having multiple days of plans, and I don't count Friday night as a weekend. So I will either have a day of shopping lunch out coffee and cake on a Saturday, or a big date night with wine and food, or a big Sunday brunch with all the pastries, coffee, smoothies and avocado, or a Sunday dinner with pudding and wine etc.
Basically I TRY to only have one big indulgence at the weekend, or two small indulgences - for example, this weekend is my SILs 18th - we are going for sushi, that I don't really like so won't eat much of and a few cocktails on Saturday evening. If I have 3 drinks or less then I will count that as a "small" indulgence. On Sunday we are going out for brunch, so depending on what I drink on Saturday I will either have poached eggs and avocado or a stack of pancakes. If I have pancakes I won't have birthday cake.
I then will probably only have something small at 4ish, soup or scrambled eggs or something.
That is the theory any way! Weekend before last I took this approach and only "gained" 2lbs over Saturday and Sunday. Last weekend I ate everything that the light touched and "gained" 6lbs, four of which I have kicked to the kerb, but I could have done better if I had focused on not nibbling and going overboard at every single meal!
I find "no snacks" at weekends is a really good rule for myself when I am at home as I have the tendency to just nibble my way through anything if not, a few almonds turns into half a bag, a little bit of cheese turns into 1/4 of a block etc.