See if you can find any guys in your area that shoot or have shot any kind of 3-position competition. They might be able to give you some pointers. As far as being better Sitting than Offhand... who isn't? There's a reason people struggling w/ Standing in 3-position refer to it as 'Awful-hand'. Sitting is the next most stable postion to Prone for most people.
Otherwise... for sitting, there are a couple variants. The one I'm most comfortable with, as it was what I learned 'back on the ranch', is the 'Open Legged' version. Basically you sit straight down on your behind, w/ your legs out in front of you, drawn up so you can put your elbows on the insides of your knees. Works well, comfortable, and you don't have to work at it very much to be able to get into it in a hurry. There are cross-legged and crossed-ankle sitting positions; the cross-legged being basically sitting Indian style, w/ your elbows in the 'pockets' on the inside of your knees, and the crossed-ankle is similar by w/ your legs partially extended. Both are much more stable than the Open-legged, but much harder to get into consistently (especially if you are a little overweight... you will probably see a very pronounced pulse from the blood vessels in the stomach wall unless you loosen your belt and unbutton your top button of your britches first), and much more of a PITA as far as scope eye relief, and canting. The Open-legged is more similar to regular Offhand in that respect: rifle vertical, head in a fairly neutral position.
Offhand... about the only way to get better is to practice. Get a .22 and some of those swinging targets or something to plink at.
BTW, I'd suggest getting a sling, a good sling, not one of those flaky cobra jobs in the sporting good stores, but either a quick adjust or a leather military sling, and learn how to use it. Quickest way to steady up your position short of leaning against a tree or fence post. Presents some interesting issues as well... like don't let the stock directly contact the hard tree or rock, or the shots will go off in weird directions. Cushion it w/ your hand or a hat or something.
HTH,
Monte
[ 08-02-2004: Message edited by: milanuk ]