Are there any videos on youtube (post patch) where people win without beating up your neighbor? That would be interesting watch.
I tend not to look as most youtube video's are just poor or repetitious.
You can do it fairly easily on Deity as long as you follow a few rules.
1. You need more than 5 cities, the more the better. the AI is quite land grabbing at Deity because each civ has 3 settlers. So build that settle and look for the best place to forward settle to give yourself more room. You really need to get cities out first and this will leave you quite behind in other areas but do not panic.
2. You now need to build your cities up just like you would at any other level get things right, prioritize, use chopping and lockdown methods to help out. make use of those City States.
3. Focus. More than any other level you need to keep focused, do not stray from your goals, always ask yourself do I really need that?... by about turn 150-200 you should be catching / overtaking nicely.
4. Diplomacy is quite important, learn to use it to your advantage.... keep your friends close and your enemies closer and all that
5. You do need an army, they will attack you, turtle, beat them off, loot their lands and take their stuff in a peace deal.
The AI has huge advantages at Deity... to win remember your advantages are....you can build more cities faster, while they seem limited. You can build better more efficiently
Winning without ever starting a war nor taking a city is harder than domination IMO.