- As you cannot directly influence the composition of these images (at least with MJ) but only indirectly by tweeking some parameters and adjusting your prompt, it usually took between 5 - 25 tries (renders) to come close to what I had in mind. Sometimes it also seemed impossible to really get there
Sometimes I just give up when I see the AI isn't understanding what I mean. But I still try changing one word or another on the prompt before. I've never gone too far like 25 renders. I usually go until 4-5 attempts, although many of the results in OP were achieved in one try.
- Rendertimes depend a lot on activity, servers were often overwhelmed so you would wait between maybe 15 seconds to 10 minutes just for one image
Here it always render pretty fast. I think I've never waited more than 3 minutes. It worths mentioning there is something called "fast" mode. By acquiring the subscription you have 15 hours of renders on this mode. After that, your prompts join a kind of row, where you have to wait other people's renders (in fast mode) to complete first, until you finish yours.
- it's a lot of trial and error but also needs some knowledge on advanced parameters to get to the desired result. Back then there were already some decent guides and a good discussion forum, so you should be able to find a lot
You can ask any doubts in Discord MJ server itself. There is a specific channel for this kind of doubt and people there are very helpful.
- imho postwork (in PS, or Gimp etc) is necessary almost always if you want to use these images in a professional context
Yes, as you can see my Neanderthal on the last image has 6 fingers. Still realistic, but MJ doesn't know counting fingers with precision.
- don't expect to get too much done with the free version, 25 renders are gone in no-time
Indeed, a subscription is a must. Paid 30$ on the second tier for a month.
Added to the personal experience of @Kryptowerk, I also wrote mine. I hope it clears your doubts out, @kryptqnick.