There are two kinds of slips: a side slip and a forward slip. Drop one wing and apply opposite rudder to induce a forward slip and lose altitude quickly.
Forward Slip to Land, Losing Altitude with a Slip
A Lost Art: The Power-Off 180 Approach and Landing - Hangar Flying
Forward Slips
Side slip preflight lesson - studyflight
How to Calculate Top Of Descent
Faulty pitot system likely cause of Malaysia Airlines 737 altitude loss, News
1 The aircraft forces in straight, level, un-accelerated flight.
How To Fly Zero Sideslip When Your Engine Fails
Slips And Skids - Plane & Pilot Magazine
Dutch roll - Wikipedia
Sideways - AOPA