At level 27, players can begin crafting Cosmic Runes. It is a wonderful opportunity to earn money for players that want to OSRS Gold concentrate on making gold while getting some RuneCrafting experience while doing so. Although it can give you adequate gold at first, it will start to shine after level 59 when you can get double Cosmic Runes as you craft.
As previously mentioned, the experience rates are rather low, ranging from 10 to 20k per hour. The gold you can get from those runes will be worth it. You should be able to create around 2500 runes a hour with 59 RuneCrafting that will produce approximately 350k gold.
Cosmic Altar is located in Zanaris which is unlocked through Lost City quest completion . There is an Agility shortcut at levels 44 and 66 that can make your trips much less difficult, but if possess the level, you could use Fairy Rings to get around the area in reasonable time.
It's a very similar method to crafting Cosmic Runes. If you completed Lunar Diplomacy quest you can begin making Astral Runes at Altar south-east of the village on the Lunar Isle. Begin by taking Runecrafting pouches, Earth staff, Law essences and runes. While running to Altar watch out for the 111 Combat level Suqahs that could strike you pretty hard if you do not make a prayer to summon melee. When you're done crafting runes use Moonclan Teleport and head to the bank to store what you made. This method can give you around 800k gold , and 30k exp after reaching level 82. This is when you can make double Astral Runes.
Another method that is profitable for making runes is via Abyss. If you've completed the the level one Enter The Abyss miniquest you can now make use of it to create Nature Runes and if not you'll need to Buy RS Gold complete the same to apply this method. Begin by equipping the amulets of splendor, and taking with you Rune containers and the essence.