I like playing score victories with poor starting locations as a way to lengthen the initial catch-up period with the AI. I don't really like spamming settlers in the early game, so I max out civs and city states so there's only enough room for 2 or 3 cities before the wars start. Sometimes I'll do this with sea level set to high, as well. Other than that, I'm mostly interested in ways of hindering myself so I have to work with the same set of challenges (poor city and district placement) as the AI. One way is to mark all the goody huts and barbarian camps with map tacks and limit future city spots to those locations. Another is to tie city expansion to governors. I'll only found new cities (or allow cities to get above a certain size) if I have a governor to place in them. This can also be done with production, by only producing units / districts when there's a governor in the city. Two mods I'm enjoying right now are Zee's Distance Matters and Zee's Properly Timed Eras. The first increases the minimum distance between cities, which makes placing more than one or two optimal cities difficult. It also leaves more room for the AI to fight in between cities. The second mod makes it harder to tech ahead of the current era and easier to catch up, which encourages the player to meander through the tech tree like the AI. ETA: I tried Zee's Distance Matters with a packed standard map, and I don't think there was enough available space for every civ to and CS to settle. About 20 turns in, Khmer's starting units came out of nowhere to steal a capital before they could even establish their own.