When you slow down (at approximately 25 knots) you will come out of ETL (Effective Translational Lift) and loose a lot of lift from the rotors so you need to pull on the collective as you are coming out (you will notice as it starts shaking.) Once out of ETL, keep an eye on the VVI (the gauge under the altimeter) and keep it above -500 feet per minute (or .5 on the gauge.) Then you just need to keep practicing until you start getting the hang of it. Smooth inputs are also very helpful.