I've cut up 2 times now, and it took a pretty well planned out supplement regimine, as well as a very controlled diet, to do this. You also kinda need to be in the newb gains area to pull this off, in my opinion.
Last time i "cut up" i ran DAA + Inhibit e + EC, plus the usual support supps: creatine, bcaa, fish/multi. I eased in to it as the addition of DAA, Inhibit, and EC was taxing my system heavily. The result after only 1 month was great, i hadn't lost strength, there was probably minimal mass lost, but my mid section really tightenend up and i was noticably more cut. I've also cut using Natadrol + EC, and that worked well too. Only reason i used the Nata was because it was free and i wanted to give it a run. Natadrol actually made me pretty hungry which i didn't like on a cut, but my strength was unreal while on it.
That being said, cutting up really isn't possible, losing weight is a calorie deficiency issue, while gaining mass is a calorie surplus issue. It just does not compute. But with proper diet and supplementation it's possible. I've always felt, and now it's reinforced with my use of AIs, that estrogen control is a huge factor in cutting while conserving muscle mass. You may not want to spend a bunch of money, but something like LX, Reduce XT, Triazole, Erase, Inhibit-e and others can be had at varying prices but can do wonders. And as always, EC is the gold standard in any type of weight loss regimine.