Have you seen Canva? I found out about it through Kim Klassen. It's a fantastic site with probably hundreds of templates, stock images (or use your own), graphics and on and on to help you make any kind of layout you wish. You can do a header/banner for your blog, a Facebook cover photo, business card, ad, presentation page...sky is the limit.
I did this is about two minutes. Yes, you can do it in Lightroom or Photoshop, but this is sooooo quick. I typically do my layouts in the print module of Lightroom and then take them into PS to add text. With this, it's a bit quicker. It's free unless you choose to use their illustrations or stock images. Those are $1 each. Most of us have a million images, so there's no real need to use theirs.
I've been missing on my blog because I bought a new Mac desktop and have been getting it set up. It's such a pleasure to use....fast and effortless. My 2009 iMac was very tired and slow and I had the max amount of memory on it I could get. It was time. Apple had my computer for a couple days to do the data/file transfer from the old to the new. I must say everything seems to be as advertised.
Go try Canva and have some fun. I think you will like it.
~ Give ~