Here are some search operators which people normally forget to use but could be very useful for essential stuff.Here they are:
1.Tilde for knowing LSI keywords:
The SERP is or will soon be depending on the LSI too.So if you want to know what google thinks are the right LSI keywords for a particular keyword,you can google like this:
Here are the LSI keywords for “buy” :shop,store,price etc ,.
2.Define operator for quick access to definitions:
Format of the google operator:
A lot more operators can be read here:
Hope that helped a bit.see you soon.