[Q] Enabling and using EXT and Swap

There are instructions and info how to format or mount the Ext2, but not on how should we make the best use of swap and ext2 ?
Automaticaly settled when mounted or? How to mount swap?

I've replaced my sd with a 16GB one, formated in cwm (1024 ext2, 256 swap and rest is fat32), then copied ALL content from old card to new FAT32.
I later used Link2sd to mount the ext2, and checked future "automatic linking" in settings.
What's the next step?

Do I need to flash the rom from scratch to fully use them?

Thx