Few things I can think of.
With the silhouette it is worth keeping the backing sheet for the cutting mat, people have a habit of throwing these away. But it stops you from needing to refresh the spray mount so often when the glue dries out.
Its generally worth using the cutting mat most of the time even if you are cutting a full width bit of vinyl. Unless you are a wizard at getting your material perfectly straight the rollers will eat it.
The blade depth doesn't need to be stuck out lots and lots if you are cutting a thin material. For vinyl, paper and thing card usually setting 2 is sufficient.
Before cutting its worth removing the blade to check it doesn't have a build up of fluff round the razor. When cleanining it beware cutting hazards obviously.
Make sure the blade is seated back where it was when you replace it otherwise it won't work very well.