Drawing assets is a huge time sink for me. I've spent some months dedicating myself to get better at it. While I can now draw some assets that's not too bad, the problem is that it still takes a way a lot of time I can be using for coding. Taking cool art and making them interactive feels really good, but drawing the cool art from scratch is very tiring for me, and leaves me more vulnerable to burn out. 

So I'm just curious: All artists, whenever someone opens up a new topic anywhere for getting a team together, what compels you to join them? What type of projects do you enjoy working on the most? 

Also, let's say I did find someone good at art and could make nice assets and animations - what actions should I avoid that typically annoy artists? And what are some things coders and game designers can do to make the job of an artist easier? 

What the things you liked the most during your times working on your favorite cooperative game projects, and what did you like the least when you worked on your least favorite ones? 

Discuss pay directly, address your budget, or your model of payment ASAP, whether you need a volunteer slot filled, paying per piece, per hour, budget, rev-share, etc. Also discuss things such as ownership of the assets, in some countries and some states emails can be used as legal evidence in court, you may want to look into a contract specifying everything to protect you and the artist.

I can only answer bits and pieces of your questions based on my experiences, but as a coder/designer to make the artists job easier, learn how to use art in any format they send, for example if they are making you 2D sprites, you will probably be receiving sprite sheets, learn how to import sprite sheets in whatever engine you are using, so that you don't have to look like an idiot and ask the artist to export every still image seperately as well as sending you animated versions for actions. Learn everything on your end, learn basic photo editing incase you need to make minor adjustments, be as clear and detailed as possible about what you want/need so you don't need many (if any) revisions from the artist. I personally like to give artists the freedom to make their own ideas come to life, i'll give a brief prompt of what i want, size, format, etc, theme, color pallet, but i don't want to micro-manage and get too particular about my vision, i want the artist to do what artists do, and make art.

Make their job as easy as possible by either knowing exactly what you want, sketching up concepts to show them so they can understand what you want, or keep it open ended and trust them to make what you want, either method can work. 

What previous poster said. Additionally, as an artist myself I can say/underline:

• Please be specific. Either hand out exact data - file format, size, colour space, file NAMING. Or live with what they give you. Don't change midway.
• Ask for a sensible amount of revisions. It must fulfil your requirements, and you don't have to take rubbish should you get it, but pixel-f&%$ing is seldomly appreciated.

• The less experienced your artist, the more guidance will be good for them.

• Be sensible about what you can get for your money. Many projects wish for pro quality but pay pocketmoney.

• Do not underestimate the power of free art. I barely do my own icons for my games, because the internet is full of free options that would eat my time otherwise (this is where your adjustment skills be come in handy).

Perhaps my two biggest artist issues when joining a team:

• Be aware that you get an artist because they have skills you do not, as well as knowledge. If you have your heart set on artstyle A, and they have five different options, look at them earnestly.
• Artists are sometimes presumed to be dreamers without pragmatism. Some may need guidance but dismissing them for not knowing programming, wishing for a more modern style than the project planner's childhood memories, or knowing better about colour palettes, will sour the teamwork experience.

About recruitment: Go to the artists' sites like deviantArt, Artstation, Reddit, ... Job offer posts today are often swamped with answers, so do take time to research your options and talk to artists directly.

Why do I join a team as an artist? If I am promised freedom BUT within a box. I personally do not enjoy the "total freedom, we don't have a plan" kind of project because it means tons of work for naught. I enjoy being either the sole artist, or if there are colleagues, for work to be split sensibly (if I do the backgrounds, someone else does the sprites, etc. There will always be overlap but being able to plan improves my experience). And I absolutely need that the rest of the team takes my work seriosuly as well - all too often some programmer art is left in the "final". If the end result looks like nobody knew what they were doing, artistically, I will be ashamed of it, not join again, and deny having worked on the project.

For me I'd join a team if the project is good and I'd get a chance to showcase my skills and creative concepts. But the people have to be nice to work with as well, that's critical! Also the project has to be conducted in a 'professional' manner. That is to say, that everyone pulls their weight (me included!) even if it's just a passion project.

Another factor is good 'planning' and specific direction when needed. I think the biggest drain on any artist is 'endless' revisions after they were asked to do something specific beforehand while the director, or whoever, keeps changing their mind or flip flopping on the previously agreed concept.

This is why I send over a lot of rough sketches beforehand and then get approval before the actual piece begins. Personally, I don't mind common sense changes - these happen. But when a client begins to change their mind constantly, as an artist you need to start charging for the extra time you spend correcting the same image over and over again.

Oh, and never use language like, "just make it pop". Because we don't know what that actually means. Just be as clear as possible. :)

Just my 2 cents.