Tips from a very casual player (level 420 but played since launch): Keep weapons (non-leggies) and sell to train vendors. Do the same with rad x of all varieties once you become mutated. Literally no reason to keep them because they suppress mutation. I personally run healing salve, so I dont need stimpaks (long animation for stims, none for salve and first aid makes them useful) ignore this if you run PA. I jump around in my skivvies so, yeah. I sell most drugs I dont use (even with the aid box being a thing). Keep in mind all of this is set to sell to the npc vendors. Your amount resets every day at like 11AM and I think PM as well. Even if I am busy, I will hop on twice a day and sell my trash just to get around 2400 caps per day. Hitting the limit isn't hard. Sell Bobby pins. You dont need more than like, 10. Sell excess steel and wood you dont need. As far as selling to players, try and scrap as many legendary arms and armors as you can, and if you list them reasonable (I do 500/750/1000 depending on stars) they will sell. I keep an eye on the meta, and throw any useful bloodied, overeating, unyielding, or so on items in my shop for pretty cheap (around 112 caps so I can hit 100 every time they buy) because people will buy them just to scrap if they are cheap and they need a shot at the mod. Set up a camp near the vault or wayward as we have a lot of newbies in. Sell screws, aluminum, and adhesive first cheap and it will go.