If you have been wondering how some bloggers pictures are bigger then your own, then I can show you an easy way to do it! Most don't know about this and its very simple to do! Nothing fancy here!!
Go to your Settings tab:
Scroll down to your Global Settings:
Click the Updated editor button in Select post editor.
Save your settings.
Now when you go to post your pictures, it will be so much easier.
Once you get the photo in the post, you just have to put the cursor on top of it and all your options for size are right there!
You can choose Small...Medium...Large...
Try it...if you don't like it you can go back and switch to the old editor.
Super simple!! Now your pictures can be any size you want!!