You may recall a blog post that I wrote regarding avoiding "easy" shots in your practice sessions and drills. Most of the drills in the 1.0 deck use wide open targets, and are set at close to moderate distance. For many folks, these are not difficult shots to execute. You can still get an awful lot out of practice on them, even as a upper level shooter. However, should you find yourself shooting 99-100% of points on the drills, at warp speed, you can definitely do some things to make the drills a more difficult challenge.
Distance: back up. This effectively makes the target smaller, and your shots become more difficult because of it. At some point, though, you reach a relatively uncommon target presentation at most of the matches we shoot - and you may run out of room on your range, as well. You can also scale the drills easier if you need to by getting closer - however, I'd encourage even the beginner to stick with the prescribed distances rather than making relatively easy shots easier. Your skill level will quickly improve to where you can make the shots in the deck without much difficulty.
Add no-shoots or hardcover: Another way to scale the difficulty up is to make the targets smaller by adding hardcover over part of one or more targets, or by overlaying one or more targets with no-shoots (non-threats in the IDPA vernacular). No-shoots are easier - you can just use another target and staples. Hardcover takes paint. If you use no-shoots, be sure to assess penalties appropriately! Again, make sure you take good notes on how you modified the drill, so that you can replicate it later to track your progress.
If you choose to scale, be certain to keep track of that in your notes so that you can compare results the next time you shoot the drill in a meaningful way.