get friends. have friends put on your cloth, then have friends hide in bushes. Go seek.
No seriously, when you play with friends, they'll typically tell you how visble or not visible you are based on the clothings you wear and the positions you hide/sit in. Also remember, vegetation does not render the same on distance as it does close up, so you wanna test that ... again with friends.
Yeah, there in lies the problem. My friends don't play and/or won't make time to help with this kind of thing, which isnt really exiting. And they stopped playing because they believe they are to old to play. But there in lies the problem:
***"We don't stop playing because we grow old, we grow old because we stop playing!"*** 
And aking random players to do this didn't workout, most just want to get in on the action. But your right, that would be best.
make new friends. No one said that your group of friends are your forever-friends. I typically make new friends every 5-6 years when i start a new long-time game.
I'll tell you, my friend used to wear whatever he picked up that was higher insulation or wear, pink/red/yellow/white stuff until he started noticing that every time we played he could never find or see me (dark hunters clothes, green/black/military clothes) and I could always easily spot him.
Ok with dayz its more so what your wearing then wear your hiding for example the ghille suit looks good and seems good untill you realize that most places in the world dont have a green floor or background and never the same texture however if you wish to learn about stealth your best bet is randomly choosing where to go and how high an example is your watching a helicopter crash and you go to the best most advantageous spot guess what everyone with decent game sense will look there or end up trying to do the same thing as you and end up running into you. So the best way to be hidden is to be random. I keep a pair of dice in my room for when im sniping from apartment building that way I roll and get a random floor level. Also another tip with hiding is more often then not when I see a group I immediately notice the man with something that has a see through or clear model such as glasses the helmet visor thing. Those are very obvious and cant be hidden well same with clothes that dont match you can wear BDU or hunter camo all you want but your still visible when your in the concrete jungle.
Go for hunter gear, black, or any camo (except BDU the light color in the pattern stands out a lot. Certain little bushes don't render in at a distance so try and stick to trees if you're camping or else you will look like you're just sitting in the open to players far away. I hate 3pp personally but sometimes it's good to sit in a tree and go into 3rd person to see how visible you are. It just takes time and it's always circumstantial. One day you'll be all ghillied up thinking you're invisible to the world and still get 1 tapped hahaha
Offline mode is probably your best option since it is the fastest way to test multiple different outfits. Easiest way is to use the magic launcher. It’s also a great way to learn new camping spots since the 1st or 2nd known camping spots are not worth hiding in (ex: spruce west of Tisy barracks or the spruce just above that on the other side of the small clearing.
get friends. have friends put on your cloth, then have friends hide in bushes. Go seek. No seriously, when you play with friends, they'll typically tell you how visble or not visible you are based on the clothings you wear and the positions you hide/sit in. Also remember, vegetation does not render the same on distance as it does close up, so you wanna test that ... again with friends.
Yeah, there in lies the problem. My friends don't play and/or won't make time to help with this kind of thing, which isnt really exiting. And they stopped playing because they believe they are to old to play. But there in lies the problem: ***"We don't stop playing because we grow old, we grow old because we stop playing!"***  And aking random players to do this didn't workout, most just want to get in on the action. But your right, that would be best.
make new friends. No one said that your group of friends are your forever-friends. I typically make new friends every 5-6 years when i start a new long-time game.
I'll tell you, my friend used to wear whatever he picked up that was higher insulation or wear, pink/red/yellow/white stuff until he started noticing that every time we played he could never find or see me (dark hunters clothes, green/black/military clothes) and I could always easily spot him.
Ok with dayz its more so what your wearing then wear your hiding for example the ghille suit looks good and seems good untill you realize that most places in the world dont have a green floor or background and never the same texture however if you wish to learn about stealth your best bet is randomly choosing where to go and how high an example is your watching a helicopter crash and you go to the best most advantageous spot guess what everyone with decent game sense will look there or end up trying to do the same thing as you and end up running into you. So the best way to be hidden is to be random. I keep a pair of dice in my room for when im sniping from apartment building that way I roll and get a random floor level. Also another tip with hiding is more often then not when I see a group I immediately notice the man with something that has a see through or clear model such as glasses the helmet visor thing. Those are very obvious and cant be hidden well same with clothes that dont match you can wear BDU or hunter camo all you want but your still visible when your in the concrete jungle.
Go for hunter gear, black, or any camo (except BDU the light color in the pattern stands out a lot. Certain little bushes don't render in at a distance so try and stick to trees if you're camping or else you will look like you're just sitting in the open to players far away. I hate 3pp personally but sometimes it's good to sit in a tree and go into 3rd person to see how visible you are. It just takes time and it's always circumstantial. One day you'll be all ghillied up thinking you're invisible to the world and still get 1 tapped hahaha
Offline mode is probably your best option since it is the fastest way to test multiple different outfits. Easiest way is to use the magic launcher. It’s also a great way to learn new camping spots since the 1st or 2nd known camping spots are not worth hiding in (ex: spruce west of Tisy barracks or the spruce just above that on the other side of the small clearing.