Make sure you know your buffers and marks. Also make sure you understand the difference between u/CTRL-R and g+/g-. Macros (q) are also useful. Also, v, V, C

Make sure you know your buffers and marks. Also make sure you understand the difference between u/CTRL-R and g+/g-. Macros (q) are also useful. Also, v, V, CTRL-V for selections. And gv to re-select previous selected area and gn / gN to operate on the next/previous match.