Start with longswords like St George's or Magdeburg since they give the best reach from horseback, and definitely grab Strong Thighs and Knight perks before trying anything serious. Practice near Sasau Monastery's posts until you get the timing right, much easier than learning during a real fight trust me. Attack from your horse's right side and keep enemies in front of you at about 45 degrees, makes hitting them way smoother. Maybe interesting start with Schemig or another slower horse while you're getting used to it since speed really changes how you time those swings.

Keep circling when there's multiple enemies and use the terrain to your advantage, narrow spots work great to avoid getting surrounded. Just remember not to let anyone get too close or they'll try pulling you down, especially if you haven't maxed those perks yet. Once you've got the basics down you can start working with faster horses but the core ideas stay the same, especially that right-side positioning thing that's honestly crucial for landing hits properly.