The last time I won the weekly drawing, I picked out a booklet called "300 Tips and Tricks for Guitar". So I thought I might pass some on to my fellow posters...

For example, Number 88: If you ever might ever do gigs standing up, make sure that you spend at least some of your practice time standing up. You use the muscles in your arms, back, and shoulders in a different way than you do when sitting.

Only 299 more to go...

I learned early to practice some, standing up. it is completely different then playing while sitting. I find it much easier if i lean against a tree or wall or car or something, but i try to avoid that also.

When I practice the fiddle I like standing up better. With the mandolin I can practice standing up but prefer sitting....with the guitar I LIKE the sitting position...the guitar is just too big for me to hold...

Tip Number 92.
If you're suffering from tension in your fingers, then you're obviously overpressing the strings. Spend some time each day experimenting with the minimum amount of finger pressure. The aim is to educate your fingers to apply the minimum amount needed to sound out the note/chord.

One way to relieve the pressure on your fingers is to adjust the fretboard action - basically the distance between fretboard & strings. When high - it is very tough to keep pressure on the strings - resulting in fatigue & sore fingertips. Most players are afraid to make this adjustment - but it is very straightforward.

Basically there is a torsion bar buried in every (most-every) guitar neck and an adjustment allen-head screw at the base of the neck. Simply look through the guitar sound hole - towards the base of the neck -and you will see it.
To adjust - place the guitar flat on your lap - neck to the left - spread the middle 2 strings apart with your fingers - and insert the allen-key in between and fish around until you find the screw-head and insert. Push the allen-key away from you - basically you are rotating the screw clockwise. Be careful not touch the strings with the allen-key since it might damage the string windings. If you can't insert the allen-key from the mid-string position - try another position - spread apart the bass or treble strings until you can locate it.

By rotating the screw clockwise - the neck will 'bend back' as opposed to 'curl up' bringing the strings & neck closer to one another. Overall you may need to rotate the screw 1/2 to a full turn. After adjusting - retune your strings and check the action by playing. If you hear any string buzzing while playing (typically on the treble strings) - you have gone too far and need to adjust back until corrected.

Intimidating as it sounds- it's easy to do -and the results are amazing! give it a try!

I would advise caution here. I've never adjusted the torsion bar (also called a truss rod) on my acoustics but have done many truss rod adjustments on electric guitars and electric basses. Always loosen the strings first and only do a 1/4 turn at a time. If you inadvertently hit the end of the truss rod travel and try to go past it, damage can result. So small adjustments, retune the strings, wait a bit and see if the neck flattens enough. Sighting down the neck you can see what is called "neck relief', or a slight bow in the neck, a little is normal. Many manufacturers have specs for each model specifying the normal relief, there is usually just a bit.

Measuring the "relief" first before adjustment is a good idea. I use a spark plug gapper.. The explanation is too long. Here's some info.
http://www.fretnotguitarrepair.com/repair/acoustic-guitar/truss-rod.php

There are other ways to lower the action, such as lowering the saddle, but amateur luthiers should leave this to a pro unless you have a beater guitar you want to experiment with-I've done this. Don't do this with your Gibson or nice Martin!

Even truss rod adjustments, a suggestion would be to have a luthier do this for you once and see how it's done properly, before messing with an expensive guitar.