There are a few things first to consider; gas, real wood burning or both using gas to start the fire. I find the latter is one to consider for someone who doesn’t have the time, skill or patience to get it started. As far as gas, these can be extremely easy to install because most come pre-made and can be installed on raised decks (usually requiring a non-flammable deck board), placed closer to eating areas (no smoke), different styles using lava rock, glass stones, big bowl styles, stainless steel. You just need a good plumber and gas (or a propane tank).
A masonry fire pit can a little trickier. First, they do make a great deal of smoke so seating should be around the entire pit or moveable based on the wind. I would also not place it too close to combustible structures, or where smoke can be a nuisance. They will need a good foundation so they don’t shift and fall apart and drainage so they don’t fill up with rainwater. They can be made of really any masonry materials; pavers, brick, fire brick, stones. One important design feature is to make them large enough to use a raised grate to promote air flow under the logs to get a good fire going. The nice thing about a masonry fire pit is that it will get hotter. The actual masonry parts will become like a radiant heater so they can really generate a lot of warmth.