What you use your ghilli for is really the deciding factor. I’ve made 3, the first was attached directly to my camies the good thing was it would stay with me no matter what. the bad thing about that was you couldn’t wash them or take them off quickly( green mechanics coveralls might help with this but won’t fix it), and the smell got so bad I was afraid it would compromise me. The second was a net I tied to a pair of camies so I could wash the bdu, that worked ok but it sucked to take apart and put back together. The one I have now is a green canvas tarp. One side has the ghilli the other side has a pack strap. It stays with me if I crawl carefully but not nearly as well as the other two. If I'm on the move I have a few carefully thought out pieces of dummy cord so I can tie it up and wear it like a poncho or I can roll it up. No need to wash, covers my pack, water proof (kinda). It breaks my outline better especially in short grass. And if you use sticks to prop it up and off you it stays cooler and you can move around a little under it. The best part was that I had my buddy look for me with his flir scope and the only thing he could see was a cold spot where I was and the hot suppressor. Also, use jute not yarn if you work in a wet climate, yarn doesn’t look right when its wet in my humble opinion.
I used a 6x8 tarp. I'm 6 foot and found that the extra 2 feet helps hide my rifle and still covers my boots when prone and makes a hood when standing. The extra width lets me lay my pack next to me in the prone. I hot-glued all the stitching holes for more water proofing and used dental floss for the thread for strength to lash the standard netting to the tarp so I could just tie the jute in place. Set it up so that you have to tie the bottom up while you are on the move or you will need to take the pack straps off when prone to cover your boots. Think out your pack straps carefully and plan to have a pack on at the same time that part was my bane. Also, I used a thick needle because I though a thin one would bend. I don’t thing that is the case anymore so get more than one size while you’re at it. the thing is heavy and uses twice the jute but It’s a hotel room once deployed. Early on I tried a quick detach netting set up so I could have a few color choices but it was a horrible failure and ended up wishing I had just made two but a man smarter than I may have better luck. Hope that helps
your going to want a two piece system. As your surroundings change youll need to reveg your ghillie, its a lot easier to take off your top and lay it on the ground to do this. Even if you have a buddy, its a pain in the ass to veg another person. also remember to look behind you and adapt to the changing environment, good rule of thumb is 30% jute 70% veg.
I agree with a 2 piece, Its so much easier to veg and small enough to wash in a 5gal bucket if it gets really smelly. Get an good boonie cover (USMC) for making a head cover. Reinforce knees and elbows with canvas/cordura or some other tough cloth.
imho the top is a bigger deal so 2 piece is nice when you can opt to skip the pants, also I suggest making a top that is chest rig friendly if your using it for that type of application. I have a canvas front traditional top and also a top cut off at name tape level for a bds tactical rig.
on the flip side 1 piece offers a no sag or ride of your suit. ive made 5 ghillies all custom to the guy wearing them hit me up with a pm if you have questions pertaining to material or whatever.
edit: kopfjager is 100% right imo. re veg is a must and will cost lots of time if your in a 1 piece.