I am currently using the vina theme and am having a lot of trouble with the image-size on various screens. Compare how the image for an excerpt of my St. Paddy's Day post looks on these three pages:
They are all different sizes and look pretty bad. Now I can only insert one picture in my "Custom Field" and I usually scale it to whatever size looks best on my home page (the first link.) How can I insert an image in my custom field that would work in all display sizes?