Any Warmachine player that has encountered a trencher-loaded Cygnar army knows the necessity of having a dozen or so smoke templates. One of the most common solutions I've seen is the 3" cardstock template. Those works great if there is space for the template on the table but sometimes you need to drop smoke on other models.
Around St. Louis, cut-out cardstock templates have been replaced by brass rings that can be found at most craft/hobby stores. These rings are found in 3", 4" and 5" diameters, making them perfect for the various AOE template sizes that Warmachine and Hordes use for cloud effects.
The handy thing about these rings is that you can drop them around and between models with little difficulty. It's possible that you may still have to drape one over a model if it's standing right on the edge of where you want to place your template, but 90% of the time using rings grants you a flexibility in template placement that a solid cutout doesn't provide.
As a side note, most folks carry these these by clipping them to the side of their army transport bag with a carabiner key chain. When it's time to play you can unclip them from your bag and carry them to the table, using the carabiner to keep them together when not in play.
You can see from the link above how cheap a handful of rings is, so I recommend picking up a handful to try out the next time you're in your local craft store.