Suturing is an intimidating skill. It that can take years to master and perform comfortably. But, no one cares about mastery when they have a massive laceration and need to move quickly. There are many techniques and types of suture methods. Don't bother learning the more complicated types, you only need to know how to do one. The ultimate goal is to effectively close a wound, promote healing, and reduce the risk of infection. I have attached an excellent video from Duke University that shows the most commonly used suture technique, the simple interrupted suture, which is basically all you would need to know for survival.
Now after watching that video once, you are a master.
When buying supplies to add to your medical kit, it can become overwhelming. There's absorbable suture, synthetic suture, prolene, nylon, cat gut, chromium, 2-0, 4-0, 5-0, round needle, cutting needles, half circle, quarter circle....and the list goes on and on. For your purpose as a SHTF suturer, you only need one type of suture and 3 tools. I will list them below
These tools and suture will allow you to practice the simple interrupted suture, which is the easiest and quickest way to close lacerations. I encourage you to watch the video and maybe practice a few times on a pigs foot. A dead one please. Again and always, if a more skilled professional is accessible or in your group please have them do it, but you should take the time to learn this crucial skill.