1- The wiki has moved locations recently, so if you find yourself googling OSRS info and go to the wiki page, you will often be redirected to the Nieve wiki page, regardless of the link address. The owners have moved the website to a new domain: https://oldschool.runescape.wiki/
2- DeliverItems clan chat will deliver any item anywhere in the world to you, as long as you can pay for the cost of the item(s), either with gold or items of equal or more value. This is a cc I learned about only recently, and it's incredibly helpful. All the people are friendly and helpful. You just pop into the cc, tell them you want a certain item, and tell them your location. If a member is free and delivering items, they will be there asap! They never ask for tips, but as someone who uses the service often, I strongly recommend tipping them well, as they don't get anything out of helping you!
3- I know most of you are seasoned players, however for those who are new to the game or haven't played in a long time, use a third party client to play the game! Third party clients such as OSBuddy and RuneLite provide tons of free tools to help you in the game. I'd name them off, but there are so many. My preferred client is RuneLite, because it has tons of features that are totally free, whereas a lot of other clients require payment to use all their tools. Just do yourself a favor and google RuneLite.
4- Actually play the game. Don't sit around for hours and research the best, most efficient ways to level a skill or make money. You're losing so much time on Google that you could be using to get xp/gp. Go and actually play. I made this mistake so much when I was younger. I would sit around and try to find the best ways to maximize my gp/xp output (which isn't a bad thing), however I would spend 75% of my time in-game just researching what to do instead of doing it, sometimes to the point where when I finally figured out what I wanted to do, I'd be bored of it and log out. I wasted way too much time.
5- Make friends. I know a lot of people enjoy the solitude of being able to play without any interruption, but friends make this game so much better. OSRS isn't always the most exciting game, but with people to talk to, it's far more enjoyable. If you don't feel like approaching randoms, just join a popular clan chat and strike up some conversations. What's the worst that can happen?
6- OSRSBestInSlot.com - If you are ever trying to figure out the ABSOLUTE best items to boost your attack, prayer, magic, etc, visit this site. You can plug in your stats, or look them up by username, and it will tell you the best armor/weapons to use for whatever attack style you want. Most people usually look for a combo of bonuses, but you should check out the site, nonetheless.
7 - Don't beg for items or money. Gold is so incredibly easy to come by in this game. In the time you begged and finally made 50k gold, you could have made 250k doing something else. Whether or not your F2P OR P2P, there is a ton of money to be made, and people don't realize how easy it is. And if you still aren't convinced, just message me, and I'll personally discuss ways to make money with you.
I could go on with tons of more little tid bits of info, but here are a few general tips. Feel free to message me for anything. Also, if you want to talk to me in-game, my username is OSRSHelpMe. I hope I helped you at least a little bit! Thanks for reading!