There are several phrases I have a particular fondness for, here are some that come to mind now.
Occam's Razor - I brought this up in an earlier blog, so I won't define it again. You may see this as a cheap attempt to get you to go back through my old blogs, and maybe its that, and maybe it's not.
Hobson's Choice - which basically states you'll take what's offered or you will take nothing at all. It is reminiscent of Henry Ford's comment "You can have any color you want, as long as it is black. This phrase goes back to Cambridge University, and people who would take horses back home for the weekend, trying to take their favorites whether they were promised to someone else or not. The stable master "Hobson" instituted the policy you will take the horse nearest the door, or none at all.
Get Bent - I do not know the origins of this phrase, is it sexual? As in get bent over. Does it refer to some sort of metallurgy like bending steel? I do not know, but I love the simplicity and the alliteration of the hard T sounds at the end.
Go Nuts - I tend to mutter this quite often, its a replacement in my vocabulary for "I couldn't care less." So when you want to do something, and I really don't care, I'll probably tell you "Go Nuts!" I know that intrinsically the phrase comes from nuts meaning crazy, but I do wonder how nuts and crazy became synonymous.
These are just a few of my favorite phrases, if you feel you can work them into your diction, please, go nuts.