Since I was about 9, I have use my "tree hook" technique for getting a "leg up". 30 feet of rope, tied in the center of a 1.5 foot hard wood stick, about 2.5 inches thick. I toss it up into crotches, the high ones it's used SRT, (hand over hand), shorter but still to high to grab, let the stick come down, sit on the stick and pull your self up (not like pulley, kind of like a vertical scoot, while taking in the slack)
Now since I'm older (more breakable) and getting back into climbing, I'm revising my skills of youth. With ascenders and a harness, foam covered steel pipe (bike handlebars) reinforce with stiched webbing for a good tie off point. Admitedly it's not as fool proof safe as a DRT, (the old up and over), but set right it wont come down untill all weight is off the line and then you still have to shake the bejeezus out of it to bring the "hook" down.
Being paded it wont hurt the trees easily, and using two, give me a chance to place multiple pitches in fast order. Like I said I've done this for years, first over the wooded marshes of Southern Florida (tree to tree), then in the BIG trees of Northern California. Now i'm working on "two hook" techniques, It takes practice to set and clean, but you can toss one in to, one tree, set the other in your first tree and slide across nice and slow, with a figure eight on the back line and ascenders on the lead line. Unlike using one and "tarzaning" tree to tree, Like when I was young and stupid and had that as a good aliby.