Here's a thought. Exercise cards.
Sometimes in magazines you'll find the cards that you can pull out of them that have different things on them. I have been finding recently that more magazines have these than I realized and I have started pulling them out and keeping them in one place to look through and attempt. The cards have different exercises on them. Sometimes the exercises are related, or follow a theme, and sometimes they don't. It's a fun way to change up your workout if you're getting bored or just need to shake things up a bit.
Some suggestions for how to use the cards...I have a ton of them, so sometimes I simply pull out three and try them. If you have enough, you can do a different exercise each day. Or you could break them up or sort them by similar exercise, or muscle groups, or body area, and assign one to each day of the week. It's up to you!
Of the magazines I regularly look through, I have found pull outs in Self and Shape. Don't discount the exercises that aren't on pull out cards though!! I have found a lot of exercises and variations of exercises in the pages of magazines.
Disclaimer: None of the above photos are of me, and I do not take credit for them, they are merely on my blog to serve as fitness inspiration and are taken from various different internet sources.