Everyone wants level 99 in a skill on old school runescape because it shows other people how much time and effort you have invested to achieve this goal. The problem is that it takes a very, very long time to get level 99. There are skills in the game which allow you to get to level 99 very fast compared to other skills. It should be noted that it may cost quite a large amount. Many players tend to buy osrs gold to be able to even afford the resources to get the 99 in the skill. Here I will show you few methods to get very high XP per hour in certain skills. Following these methods should boost you to getting that level 99 you always wanted, then you can flex on people at the Grand Exchange.
The first method to getting very high XP per hour is fletching. Fletching darts is something which you can literally stand on a single tile and do all the way to 99 but it does require a lot of clicking on the screen. This can be done easier on old school runescape mobile as you can click in two spaces a lot faster. You should expect to make a large loss during this method and you should have a large starting cash pile. If needed, you should buy gold to achieve 99 in fletching.
Cooking is another very fast skill to max out and can once again be done so while standing on one single tile. Mixing a jug of water and grapes together gives you a jug of wine. After waiting a few seconds without make more jugs of wine, you should receive a very large XP drop. Once again this is a very expensive method to get 99 but this is expected for such high exp per hour. Buy gold if necessary.
Magic is a very useful and fast skill to max out and is very, very expensive to do so. A lot of expensive runes are needed to burst in the caves of monkey madness 2. The quest itself is a high requirement to even complete.
Prayer is another skill which is very easy to max out however is it fairly click intensive and requires attention to the screen. With the introduction of the new hydra boss, hydra bones can give you around 400 to 600k XP per hour which is a new method to prayer. Superior dragon bones are very good to getting to 99. Once again, prayer is a very expensive skill to train and get to level 99 with so you do need a good, high cash stack to start with.
A free method to a fast 99 is to train fire making through the wintertodt skilling boss. This is absolutely free to do but you may need a few pieces of food per kill but nothing too extreme in price. As you level up, your xp per hour will slowly get boosted up. You will also make a decent profit on the way to 99.