Reddit mentions of Blue Force Gear Vickers 2-Point Combat Sling, Black

A miniature sewing kit. When you’re running missions outside, clothes tend to get ripped, and with only limited numbers, life can get rough. A sewing kit helps.
Spirarcha chili sauce. If your soldier likes spicy foods, send them this. It’s spicy, it has flavor, and it will last them a few months.

Socks and underwear. Send them hiking socks and replacement pairs of underwear. Clothes tend to get gross and if they don’t have laundry, sometimes it is for the best to toss out old underclothes and wear new ones.

Beef jerky.

Trail mix of various types.

Great ideas for one-time gifts. These range from relatively cheap, to pricy and are a great surprise to a soldier stationed anywhere. I’ve included links to the products to give you an idea of what they look like, though don’t take those links as the only/cheapest place to find them:

Adjustable two-point sling. On base they have to carry around a weapon everywhere, and on mission they’ll be going some serious distance with it in their hands. If they are still using an Army-issue plain sling life is going to get a bit annoying. An adjustable two-point sling makes things more convenient and lets them ready a weapon to fire without an awkward movement on a mission. Ignore this if they are using a machine-gun, because those use heavy duty slings. Various companies make these, I prefer the VTAC, but they are all similar in make.

Surefire Earplugs. On mission, soldiers are supposed to wear earplugs, but many don’t because its uncomfortable and often all they are issued are cheap low qualifty plugs. Surefire earplugs conform to the shape of the ear and they are designed to allow someone to still be able to hear conversation level noise while protecting from high level noise. These are great.

Head-Loc helmet straps. One of the greatest pains is a helmet that won’t stay secure. The Head-Loc straps stay tighter and make the helmet so comfortable that you forget you’re wearing it.

PMAGs. Magpul plastic magazines, or PMAGs are high quality replacements for metal GI magazines. Army issued metal magazines are often used for years past the date that they should be retired and they are prone to feeding issues (I won’t get into the details) and PMAGs fix many of those issues and give a soldier more confidence in their equipment. A combat load is 7 magazines, so don’t feel the need to buy more than that, and even one or two PMAGs is greatly appreciated. Ignore if they are using a machinegun.

Head-lamp. Walking around an outpost at night is tricky and Afghanistan can get dark, a head-lamp is a great help to keep your soldier from stubbing their toe or walking into barbed wire. Get only with some kind of red or blue light filter.

Mechanix gloves. Soldiers need to wear gloves on mission and they tend to get torn up, a replacement pair of mechanixs gloves is a good choice.