Let me begin by saying I am NOT an image expert by any means. There are much more experienced bloggers out in Cyberland, but I really like paying it forward. So...here we go...
Making it Pinworthy
I use a combination of Powerpoint and Picmonkey to enhance my images. With Powerpoint, you have two options. You can use the design tab and make your photo the "background" if your slide size is a similar shape to your photo, or you can insert the photo as an overlay and just layer text boxes over the top. With the image above, I made the photo my background, but I had to format the background offset so the image wasn't distorted. Once you're happy with your slide, you "save as" a jpeg or png file and upload it into your post. Many beginners insert their photos "centered". Do not feel nervous about moving them to the right or left of text. All you do is click and drag it where you want. If Blogger doesn't cooperate, then you can always delete and retry with your cursor in a different location. You can also resize them. I use a variety of sizes and have actually gotten brave enough to resize photos to a custom size in the html side of blogger, but I don't recommend that unless you're familiar with html.
I mentioned Picmonkey earlier. Sometimes, I use Picmonkey to edit a photo, to create custom sized graphics, or for the collage option. You can easily add frames, edit the photo, add overlays such as ribbons, labels, or partially transparent shapes. Picmonkey also allows you to use your own fonts with their program, and I love that I can grab the resize buttons of text boxes and stretch the text to the exact spacing I want. For details on how to use Picmonkey's features, check out this video (and search for others on Youtube). Picmonkey is such a great FREE site, but if you see "royal" features you like, I personally feel it's worth the $4.99 a month price.
Image Editing Features in Blogger
Once you've prepared your image, the important work begins. Remember, your images are pinned, so think from the pinner's point of view. A year from now, what will the pinner need to know? They will need to know where the photo came from, so be sure to watermark EVERY image in your post. If you went to my archive, you'd see that watermarks are missing on photos I used. Guess what I'm working on this summer?? Do what I say...not what I did!! Before you put that photo into your post, make sure you have done this step.
After you insert the image, you will need to take care of a few more steps. So that I don't forget, I always take care of labels and my search description first. You see these post settings on the right side of blogger. If Search Description is missing, you need to check your blogger settings (Search Preferences) and turn on the Meta Tag.
[THIS POST] on CHALK AND APPLES will walk you through how to fix the pin it button on your blog. Again, remember the goal is to make your content work for the reader, and the description helps those who pin from your blog as well as pinners who happen to see the pin on Pinterest later.
Image Size for Social Media
Sharing your post to social media is the final (and probably the most important) step, but there are important considerations for this too. [THIS POST] includes all of the dimensions you need to know for social media. I recommend you create a file in Powerpoint with the slide dimensions preset for each social media site you plan to use. Of course, Instagram is easy. Any square image will do. You'd likely want to share to Facebook too, so make sure you have a landscape image (or create one) that you will use there. It does not have to be part of your blog post. For this post, I made this image for Facebook, but again, I don't always include that image in my post, but rather just get the post URL, write up a post description, and insert the image I've made.
Have a great weekend!