I got my Selective Service Notification at age 18, was Field Artillery, then got switched to U.S. Army Special Forces Long Range Reconnaissance Patrol and U.S. Army Airborne Ranger, 4 Man L.R.R.P. Team spending Weeks in the Jungle without being detected by the Vietcong and North Vietnamese Army while performing Special Surveillance and Special Reconnaissance. Later as a U.S. Military Officer, I graduated from the U.S. Army's Jungle Warfare School when the School was still at Panama.
Rescue tips, Pillar of Smoke by Day, Pillar of Fire by Night, in other words gather as much wood as possible as if your life depends on that (it does), in the Day make a huge smoky fire, at Night make a huge flaming fire.
U.S. Army Issued Wool Boot Socks, Wool socks allow moisture to escape, Cotton keeps moisture in so you get "Immersion Foot". The towel we wore around the neck during the Save Democracy of South Vietnam War was to dry our feet, the towel dried out faster from body heat from around the neck.
Navigation in a Jungle (what we could not do in combat), line up two trees going in the direction you are going to, mark the trees by scraping the bark until white shows, the marks being squares or triangles as something that does not blend in and can be seen from a distance, kind of like sights on a rifle. You keep doing this to other trees before you get out of sight of the trees you previously marked. So that you are not walking in circles.
Banging Metal against Metal can be heard from longer distances than yelling. So can a cheap whistle. Two stream rocks or river rocks banged together makes a loud artificial clacking sound heard for a distance, use a larger flat rock and bang that with a smaller round or oval rock, face the flat side of the larger flat rock in the direction you want the sound to be heard, bang on the side facing you with the smaller rock.
Marking where you are at a river bank or stream, the object must be vertical and horizontal, like a cross, at eye level. Vertical only will blend in with trees. Add bright cloth if possible. Make a man sized or larger stick figure if possible. Make sure you scraped the bark off the branches until tan or white, use a sharp rock if you don't have a knife.
Walking "Stick" 6 feet to 7 feet tall, one end sharpened, 1.5 inches thick. Uses described in Boy Scout Manual. Two of these plus a poncho equals a two person carry emergency stretcher.
Non Combat, if lost, stay were you are, Extended Camping. Traps and Snares. Smoke meats into jerky to preserve, place food into bag, save some on your person and hoist rest in bag into High Tree Branches unless there are monkeys (that will steal your food). Eating snakes cut about 2 inches behind the head, so that you don't poison yourself.
As U.S. Army Special Forces L.R.R.P.s we usually carried. 4 Waterproof Bags (Cloth lined with a rubber coating) also used as flotation devices inside our Rucksacks. U.S. Army Issue Poncho used as a Shelter or stretcher. 120 Feet of Rope, of the U.S. Army Mountain Climbing Type, 6 foot lengths of same kind of rope. With lanyards attached U.S. Army Machete each, U.S. Military Aviator's Survival Knife, U.S. Army Issued Stainless Steel Pocket Knife, "Commo" pliers. Zippo Lighter with small can of lighter fluid (eventhough we could not use fire while on Mission). Two Weeks of Freeze Dried L.R.R.P. Rations, could be rationed to one month. Two Two Quart Collapsible Canteens with bottles of water purification tablets. Towel worn around neck. Parachute Cord. 1 PRC 77 and two extra batteries, one long antenna and one short antenna per Team. Compasses and maps. Stainless Steel Signal Mirror. Medic First Aid Kit with morphine syrettes. Camouflage Sticks and Insect Repellent. One roll of 100 Mile an Hour Tape (O.D. Duct Tape). U.S. Army Arm Sling worn around head like a bandana. Flashlight and extra batteries that we rarely used. Memo pad, pencil, U.S. Government Pen inside of plastic bag. We made our own metal bandaid box survival kit that included fishing line, fish hooks, sewing kit (could be used as sutures), waterproof matches, a whistle, a button compass, single edge razor blades (kept in a buttoned pocket). Issued U.S. Army mechanical wrist watches. 2 Identification tags worn around neck, 1 identification tag wrapped in black electrical tape laced into each boot lace. Packs of cigarettes not smoked, used like chewing tobacco as a stimulant. As many packets of instant coffee and sugar packets we could get from Combat Rations, usually popped into mouth not mixed with water while on the move (U.S. Army Ranger Training). Just before night we climbed up trees tied ourselves with the 6 foot lengths of rope, as there were apex predators at night. We Never carried a 100 pounds like the "Grunts" and U.S. Army Rangers, we moved fast, silently, and covered our tracks.