I seem to remember reading that Yang Cheng Fu advocated doing the form three times first thing in the morning, then again at bedtime.
Again, that's from memory. I could have that confused.
I also recall he said not to practice where there was bad air or insufficient lighting. Not to practice where it is too cold or too hot. Not to practice after ingesting too much alcohol or right after eating.
That said. I can only tell you my regimen and then kick back and wait and see what others think.
I practice second thing, every day.
I get up, start the coffee pot, do five minutes of standing meditatin in Preperatory Posture then I begin to do my warm ups.
I go through the entire set of warm ups that Bill Wojasinski taught me, then I go through a lot of the Wu style warm ups I learned as well.
I don't think you can do enough warming up so I do as much as I can every day.
After I'm good and warmed up, I start out with the Wu style Tai Chi Walk. It's similar to Mao Xing Stepping, but without all the toe angle re-adjustments and rocking back and forth, it really gets you moving from your center and is easy to do that early in the day. After twice across the room and back doing that, I then go twice across the room and back using Mao Xing Stepping.
Once I've done my stepping I begin to do Chi Kung. I have several different sets that I do. Some I got from the Wu family, others from books and seminars I've read and attended. I do this for approx. fifteen minutes.
After Chi Kung I do a very slow Yang 13-posture form.
After the 13-posture form I do a slow Yang long form.
If I have time after that I do the long form again. I'd say this is only about twice a week though.
Then I have to wake up my daughter and get us both out the door.
Once at work I usually sneak off after about an hour to a little room I know of where I have complete privacy and I do another long form. If that room is in use, not too often, I have a hidey hole at the bottom of a staircase where I can do a 13-posture form. If I have to do that I do the 13-posture form three times instead of one long form.
I usually do this three to four times during a work day. At least twice, usually three and sometimes four.
When I get home on nights I don't have class I immediately set up and do some sword form training. I practice off the DVD of the Grand Master and Master Yang Jun, using what I recall and the notes I made from the sword form training I took at the seminar with Master Yang Jun last year. I'm not very good at it, but I enjoy it and I'm getting better every day.
That's all I can sneak in usually.
On nights I do have class I go to class and that's all I do for the night.
On nights I don't have class I will do one more quick set of warm ups then a long form or two about an hour before bed if I have time, but that's not often, maybe twice a week if I'm lucky.
On the one night a week my practice partners show up, we push hands for about an hour or more. On those nights I don't do any form training afterwards, usually because I'm pretty well exhausted by then.
Well, that's how I train. It may not be enough to get me to Master level in ten years, but it's all I've got the time for.
Maybe once I hit the lottery and don't have that pesky job hanging over my head every day I'll be able to do more than that.
Hope this helps some with what you're looking for.
I'm sure others will have more and better insights into what the "recommended" amount of practice is.
I have never paid much attention to direction to face or anything like that for form practice. I practice in my living room, or out on my deck, or in my basement where I have a small (very, very small) studio I use for our push hands sessions.