Trial and error is the key, but the length of the top link is really everything...the longer you set the link, the deeper the angle it cuts when pulled forward...which is how it works best. If you try to cut to deep an angle, it will simply stop the tractor. You will have to keep the trip lever well greased, and a good heavy rope is needed to give it a yank. I find it is best to simply tie the rope around the seat so it cant fall free and tangle in something. Also keep in mind that some ropes have a lot of 'give' - you dont want this, since it takes a bit of yank to trip the lever when fully loaded.
Anyhow, the only time to have the bucket pointed backwards is when moving material from a pile. Otherwise, pull it forward....lots of fun once you get the hang of it.