Hello, as some of you may have seen from my previous one or two posts, I'm new at playing guitar. So far, everything I have been learned, I have learned sitting down. I recently attempted to play some chords and such standing up and for me it felt completely different. I had to get use to the spacing between the strings again and get a feel for the neck. I know this seems like a stupid question, but does anyone have any suggestions on how to get a better feel when playing standing up or is it a matter of just continuous practice?
practice playing standing up if you're going to be performing (that should be a no-brainer, you wouldn't practice sitting for a standing performance) and shorten your strap
You can do a couple of things. Bring the strap up higher the correct form. You play sitting down with the guitar closer to your chin than you would standing since the guitar has no support from your lap. Having it up higher is much better for access to your fretboard and all the "good" musicians play like this.

If you choose to keep it lower than that you could have the more so vertical than straight out.

Or do a Slash, walk around hunched and/or to the side or, with your knee supporting it whilst resting on a amp or whatever you might have.
Yeh man it all comes down to practice. Having experience and developed confidence playing standing up will improve your overall playing as well. Concentrate a lot on wrist control, you fingers will eventually stretch out an get used to the fret board. I had more problems starting out with picking control and where my picking hand rested on the guitar. Experiment and find what grooves for you. Its all a matter of ones own comfort zone, but don't be afraid to stretch that comfort zone, that's where you'll surprise yourself.
Just practice standing up and sitting down equally if you can. Standing up causes you to use your muscles slightly differently, and because playing music relies just so much on muscle memory and familiarity, you have to get used to it.
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Bitches be Crazy.

If you position your guitar in the same position it will be in when you stand up. You can sit down and practice then once you stand up it wont feel any different because it hasnt moved positions on you.

If your a right handed guitar player (pick with right hand) then put your guitar on your left knee, this is called Classical position. Also, get a footstool or something to rest your left foot on or it wont feel right and you will be forced to slouch, which in turn isnt the same way you would be when standing.

Ultimately, it is best to practice standing up. I know myself i like to sit when i practice so what I do is I go half and half. Half my practice standing, and the other half sitting.

Hope this helps.
I'm a fairly new player myself and had to adjust the strap in order to be able to play properly while standing up. You'll also notice a big difference depending on the guitar you play. A jumbo acoustic is a lot harder to get your arm around than a small strat.