Landings are controlled with the throttle and elevator as most are stating but if you haven't got the feel for the flare you should go practice a bit longer. Elevator control is a must. Some other little things that may help are the props you use. I use long props with light pitch and the prop acts like a breaking action. Once in a while I use a three bladed prop with some plane/engine combos and the breaking action of a three blade prop will slow a plane down. As LN stated, it's the drag that slows and some props just seem to add to that. A new pilot may over control the elevator and induce a stall if you slow too fast. Just start shooting some approaches or false landings a couple of mistakes high so you can get a feel for the landings. After you get it down do a lot of touch and goes during your day. It all comes to you with time and practice.