If pressed for time I use the "what if" method almost exclusively.
I get all the information on the digital page, then start with the what if.....
- What if I use a red sans serif for the headline?
- What if I set the body in two columns?
- What if the body is in three columns?
- What if that were green instead?
- What if I reversed that subhead?
- What if this were monochrome?
- What if I vary the type size for the header?
- What if that were larger and aligned right?
- What if I made the grid larger/smaller?
- What if this were exclusively for women?
- What if I use the colors I saw last night I liked?
- What if I put the header at the bottom (for banners)?
When I first started out, I worked in a fast paced production-oriented position which required me to often complete 80-150 various layouts in a single day. Things like business cards, fliers, postcards, etc. And I was the only creative as you've mentioned.
I found, for me in that situation, that often the best work came from simply avoiding anything I had done before. If I laid something out and then thought "Wow, that looks very similar to that thing I did last week." I'd redo it. This forced me to discover new solutions to common design problems. I'm generalizing. I'm certain at that pace I repeated some layouts, in some degree, at least once. But with the "what if" method I learned to explore colors I normally wouldn't, or positioning which was not always "traditional" but still worked for that project.
Templates also help a great deal. Not full blown templates but off-hour sketching. You can sit watching TV at night with pad and pen and simply rough out some various layout concepts for various things. This takes little effort in general. You don't have to deal with the on-the-job pressure of "GET ER DONE!" and can simply jot down variations quickly as they come to you. You don't even need to take the sketches to work. Simply putting them on paper will help flex the creative muscles.
I find I often have ideas or notice things I find interesting simply doing regular, everyday tasks. I'll see a label in the grocery store I really like the color use on. Or, I'll see the titles for a movie and really like the general layout used. For me, it's these small things I need to recognize as inspirational and hopefully utilize some aspect of them. By just sketching whenever I'm sitting and basically doing nothing else I learn to solidify the concepts of things I like or want to try. Then when I do sit down to work, those concepts are more easily recalled.
Oh yeah... and...