Lateral work can be used to steady and improve the regularity of the rhythm of your horse’s gaits. Particularly with horses that want to rush and/or become irregular, asking for a little shoulder in, leg yield, or a few steps of spiral in or out, can help them wait and find more cadence in their stride.
"As the beginning of the session should be, the end of the session should be: long neck, stretch over the back, swing." ~ Carl Hester
Acceptance of the outside rein is key to resistance free downward transitions.
You should feel like you have to ask your horse to stop, rather than simply "letting" him stop. If he stops when you let him, he is behind your leg.
To successfully maintain the elusive forward feeling hands, imagine that you are pushing a shopping cart as you ride forward into the bit.