Which technique should I use?

Good morning RIU,

This is my first post on this site and of course it is a some what mundane question. I've been growing for a few years now and I'm looking to try something new.
My grow room is 3 feet by 5 feet so quite long and narrow it's also quite limited in height, only 5 feet. It is lit by 2 x 400w HPS and I have a rather basic DIY CO2 system.

All of my previous have been short indica dominant plants and more recently the auto-flower variety's, I've generally crammed 12-15 of them in the room and gone for a SOG style grow but without any pruning etc.

Now my question to the people of RIU is what would be the most effective use of that space, what technique should I use on this next grow? SCROG, LST? Any reasons you can give for your choice would be really appreciated.

Thanks,

TheBlackLab

I'd also like to add that I'd prefer to grow in soil as I have a copious amount of it.

Thanks again,

TheBlackLab