Hi ergceo. I'm assuming you're talking about hunting at long ranges. I hunt mostly deer and elk in Wyoming. In the last 4 years I have set my guns up to shoot long range. Number one. You need an accurat 1MOA or less rifle to play this game. If your, there are some nice rifles out there. If you don't reload, shoot until you find a round your rifle likes. I have a Weatherby Vangaurd that groups .5-.75 inches at 100 yards. Not bad for a $400 dollar rifle + a Timney trigger for $130. I have a Bushnell 4200 4-16x40 with Kenton wind and elevation knobs. It sets in an Axiom stock with a Limbsaver recoil pad. (I'm only 150lbs and not a fan of recoil). I also carry a cheekpad in my bag for practice to protect my face from muzzle jump. I can put a 100 rounds in the prone position in a t-shirt and not feel a thing. I bedded the front reciever lug. Harris bipod ($120) with pivot for terrain. This is my backup rifle. I switch over to my primary hunting rig a couple months before the season. Same caliber with exact scope and ballistics. I only have a Limbsaver on it and tend to shoot only 20-40 rounds each practice session to save barrel life. Also, Catfish is right. You will need a good range finder capable of 1000+ yds to get fast and more accurate readings. You need a proper scope set up for your ballistics. I have dials made by Kenton Industries set at averages for my altitude and temp. My guns are set at 8000 feet and 50 degrees. Most of my hunts are between 6000ft-10,000ft. For me my max range is 700yds. My shots will be within +or- 4 inches with my 300 win mag at any of these elevations or temps. Do your homework using ballistics software like Remingtons to test your theories. Everybodies skills are different. Your style is similar to my hunting style. I prefer to shoot prone. I prefer broadside standing still shots. I have no problems sending rounds out to 500 yards in the seated position with my harris bipod. Beyond 500yds, I really prefer to be prone using my hunting pack(which I use to practice) or my bipod. And since I'm a hunter, I will always try to get as close as possible before attempting a long shot. Still, I practice(Very Key) out to 700 every week for a couple months before the hunting season starts. Work on all the positions you are comfortable with. Prone, kneeling, sitting,etc... Laying on a side hill, downhill, uphill, level terrain, etc. I know it's work, but it will pay off.
As for the shot...and others my chime in here...I'm not an expert, but, I am a pretty decent shot
1-Stay loose. Get comfortable behind the gun. If you feel out of position, you probably are. Sometimes terrain will not allow it. Make the best of it. Develope a routine for consistancy. Here's what I do....Check range. Check parralax. Check for correct BDC, or elevation and wind dials. Check safety. When sitting or kneeling, I push into my bipod slightly to stabalize. Exhale and hold. Nice trigger squeeze. Easier if practiced consistantly. Prone. Same, except, my free hand is under the buttstock being used to help make slight correction in aim by stalbilizing the rear of the rifle. If I'm using my pack, my free hand stays clear. The pack Is more stable than the bipod. Only my trigger hand is on the rifle.
2-Concentrate on your crosshairs. An animals front legs are usually very close to perpindicular. Make sure your scope is level by using there legs as a reference( same with target when you are practicing. just make sure you keep your targets pretty level). This will keep you from canting the rifle, also. Not good for long shots.
3)Your probably already familiar with breathing techniques. I'm sure you know, when hunting, the pressure is on. If you have time, work the trigger a couple times. I have a snap cap and will use it on animals I never intend to shoot. Even when hunting, you can still be practicing. I often do this a couple times early in the my practice sessions to loosen up. Later and just before the season opens, I always send a cold one down range to see how Me and My rifle are doing. You don't always get a second shot. That first shot is the most important. I always pick a range between 400-700 yards. This is the only test, IMO, that is the most important. I set up 3 to 4 targets and shoot one round into each in no particular order. This style of shooting doesn't allow me to get into a groove. Remember: I'm not a bench shooter. No offense. I'm a hunter and I practice as such. The only time I send two rounds is when I'm practicing fallow-up shots.
Hope this helps a little. Sorry if it's a little dry. Just remember the most important thing here is practice. If you shoot 100-200+ rounds this way, you will be 100times better than the guy who goes out and shoots a couple rounds just to see if his rifle is on. It's not very ethical either. Practicing this way, I am able to send single rounds on targer(I shoot at 8 inch shoot-n-see targets) out to 500 yards in sitting and kneeling positions pretty effortlessly. In the prone, 500-700 yard shots for me require good breathing technique and a good trigger pull. Know your rifle. Know your scope. Know your limitations.
Best of luck and get out there and shoot!!!
Practice. Practice. Practice.