Incremental search forward

Well-known incremental search forward(isearch-forward Lisp function) which is invoked with C-s has also additional useful key-bindings which I use often to instruct what to search. After you pressed C-s in buffer they are:

1. C-w to yank next word or character in buffer onto the end of the search string, and search for it. You can repeatedly press C-w consuming next word or character.
2. C-y to yank rest of line onto end of search string and search for it.
3. M-n/M-p to search for the next/previous item in the search ring.

As usual for more information read help (C-h k C-s or C-h f isearch-forward RET ).