https://blog.techorganic.com/2016/03/08/radare-2-in-0x1e-minutes/
https://github.com/radare/radare2/blob/master/doc/intro.md

[Analyse]
is                      list symbols
iz                      list strings
ie                      entry point
axt                     find reference to var/func
axt @@ str.*            find references to strings
afl                     list functions
afn                     rename function
afvn                    rename var
VV                      graph mode
CC                      add comment
fs                      list flag spaces
fs <flag space>; f      list flags in this space
? <...>                 evaluate expression
ahi s @@=0x... 0x...    manually recognize strings at offsets
!rahash -E rot -S s:13 -s '<...>'   Rot13 string

[Visual]
g<id>                   follow call
u                       go back

[Patching]
oo+                     reopen in write mode
ood                     reopen in debug mode
w...                    write cmd

[config]
eco <theme>             change color theme
e asm.pseudo = true     show pseudocode in disasm
e scr.utf8 = true       better arrows