Nothing is more stressful for me in this game than socketing my gear. The emotions, the hope and then the madness that gets me when my 5th socket fails it can not be described in words(well maybe it can but i would not use those words on public haha!).
At start i used to just spam manastones in and clearly that was a pain. Then i started to wait a few hours before i try to socket another one after a successful try.
And then in a conversation with someone i got this awesome tip! I have tried it and yes it improves your chances greatly even if sometimes it will fail, you still have more chances and you will use way less manastones this way!
Basically the idea is use white manastones to socket another item preferable high level items so the manastones will fail, once it failed twice make a try on the item that you want to socket.
Also i always make a break after i successfully socket. A few hours or so, not sure if it actually helps but i like to believe it does.
With this method i managed to socket all my gear and it rarely failed.
Like i mentioned before there is still a chance to fail but it is a smaller one. If you are really rich maybe you can use supplements to boost your success rate. I'm too poor for that and even if i wouldn't be i don't think i would pay that much!
Have fun and may your sockets be full!