Install programs files to separate disk to OS

I am going to install BunsenLabs Crunchbang on my laptop that has 250gb SSD and a 1tb HDD. I am coming from a Windows 8/10 background so I am not familiar with the way the file system works. I want to have my OS files on the SSD with the majority of my programs installed on the HHD. Yet I would like some programs installed on the SSD. How would I set the drives up to achieve this? Do I need to partition the disks on install or is it easier to change each program's install directory individually?