I'm 5'10" 148 and have decided recently to go up to 155. I stopped around 145 when I initially started to put on weight going from ~120 when I was 18 up to 145 at around 20 or 21. I've just kind of cruised there and just went into maintenance mode but decided I wanted to put a few more inches on my chest, arms and legs. Unfortunately I've somewhat forgotten how to actually put on muscle since I've been cruising for the past 8 years or so. This has been going on maybe 3 weeks now and I've only gained 1 pound but I can already see my vein definition in my arms has returned to what it was when I was putting on weight at least. My wife did also comment it appears like my chest is larger as well. I've also noticed I require at least 1 more day of rest compared to back when I was 20 doing this.
My main change is not really doing heavier weights but doing more emphasis on the negative rep. So I'm still doing my normal bench rep weight (which I'll probably have to increase in a few weeks) but just doing it much, much slower. Some deal with my bicep curls and my squats. I also do more sets. And I'm back to eating tuna like I'm Japanese.