I beg to differ slightly with zgirll's recipe, which is not to say anything bad about her grandma but merely to suggest that there's more than one way to go about a fried egg sandwich. In my version, you can use as many eggs and as many or as few condiments as you want (these are optional, though I wouldn't dream of eating eggs without salt, but obviously the eggs are essential. Yeah, I know. Thank you Captain Obvious.). For the record, this is the one and only time I'll recommend tomato in any form with fried eggs: a few slices on the sandwich are a nice garnishy touch.
I suggest making your fried eggs sunny side up or over easy. If you prefer your yolks well-done, break them at this point (sigh! growing up, my family called these "messy eggs" and they were acknowledged as the failures they were) Otherwise, don't break the yolks until you go to put the eggs on the bread (and I do agree it should ideally be good crunchy bread). Let the bread soak up the runny goodness, and try not to let any drip on you when you eat your creation. Who needs mayonnaise when you have fresh, warm eggy goodness instead? Plus it's all the more incentive to eat quickly (this is a great, albeit messy, fast meal if you're craving something warm).