I spent my childhood using a push mower to tackle the not insignificant amount of yard owned by my parents. That mower weighed what seemed a thousand pounds, and was possibly last sharpened in the early 1900s, when it was fresh from the factory floor. I think it might have been cast iron. I think it probably should have been donated to a World War II scrap metal drive. Take these illustrations, then add some rust and make the wooden parts kind of rickety, and you have our mower. However, I wouldn't have traded it for anything, mostly because it was such a good martyrdom aid. Eventually using it became so onerous in my imagination that I decided I could get away with charging my parents a certain dollar amount for each portion of the lawn I completed. I guess they didn't want to use it either, because they actually paid me. Thanks for enabling my book-buying habit, mom and dad!
Being the proud operator of a push mower, rather than one of those fancy gas- or electric-powered mowers, you learn all sorts of tricks. Most important is not to let the grass get too long, because otherwise you end up having to use a scythe (only tried that once) or maybe a pair of garden shears to trim the entire lawn. Either that or going over the same area twenty times with the push mower. Number of times I have let the grass get to long to effectively mow in the twenty or so years I've been using a push mower: countless. These days when I do it I at least have recourse to my handy Black and Decker edger, which means I can edge the entire lawn if necessary--but that leaves my arms feeling like I've been using a jackhammer, and defeats the purpose of using a push mower in the first place.
One of the big enemies of the push mower is the lowly stick--even surprisingly small ones. Hit one just right, and your forward progress immediately stops, usually leaving a mower-handle shaped bruise on your stomach or other, more vulnerable parts. It's important to learn how to recognize which sticks are going to be problems, and which sticks you can mow down with abandon. Wise people remove larger sticks before they get started, but as a child I was never that thoughtful. Problem sticks that you miss will need to be unjammed with a swift kick to the mower blades (see footwear tip below) to get the mower to spit out the obstruction. Sometimes this results in a sore heel. Sometimes the operator is thankful that the mower blades aren't that sharp. Another useful tip is not to mow the grass in sandals. This is probably true for all mowing, actually, and especially true for mowing just after it's rained. It just takes a while to get all those grass clippings out from between your toes.
Keeping all these things in mind, I highly recommend using a push mower if you've got a reasonably small piece of grass to keep trimmed. Not only is it you-powered, necessitating neither electricity nor gas, it offers a wonderful opportunity for meditation on the natural world, your neighbor's disgustingly well-kept yard, or your arm-length to-do list, all with the background noise of a soft whir of blades (and the occasional cursing caused by stick encounters) rather than the roar of an engine.