Here are some tricks I collected for making Notepad++ a more comfortable text editor for me in general in for the R programming language
Switch between tabs in Notepad++ with Ctrl-PageUp/Down
Notepad++'s default behaviour is to use Ctrl+(Shift)+Tab for tabbing between different text files. This was very annoying to me,
because other programs I use, such as Chrome and Excel, bind these functions to Ctrl+PageUp/PageDown.
Today I found a blog post by Yawar Amin
which shows how change this behaviour.
Add autocompletion for R functions
Yihui Xie shows on his blog how to add autocompletion
for R functions and symbols to notepad++.
The Npp2R does something similar but less customizable, and does also contain
additional functionality like code passing, but I did not look into it in detail.