I'm not very formal with my conditioning. I do some cross training. I did have a more "serious" conditioning schedule when I was first getting my mare in shape. For a couple months, I rode five or six days a week, 8-15 miles a ride. Baby Girl holds her condition very well, so she stays in shape with a fairly small amount of work.
Typically, I'll ride four days a week. Two of those days I do arena work for about an hour a session. Walk/gait/canter. We do a lot of dressage style things, working on rhythmn, suppleness, and lightness. It gets her relax and stay quiet. She's a hot horse, so working quietly is important. We jump sometimes to mix things up.
The other two days are spent on the trails. One of a "fast day". We do somewhere between 8 and 12 miles, keeping a 10+ mile per hour pace over all. The other day is almost always a Saturday, where we go for hours. We try to spend 5 hours on the trail at an 8 mile per hour pace.