Totally depends on your skill level. I'd make it look horrible. Others could do a fine DIY job.

I know it’s not the same but redoing our baseboards post flood was easier than I expected but required tools we borrowed from a friend. Crown seems much more visible to the eye and like I would want someone better than me to do it.

" If you need to ask, it's probably not DIY. "

I would agree with this statement unfortunatley. Compound miters are not for everyone.

Do it yourself. Then your question will be answered without question.

Agree with all above. Unless you really are skilled in woodworking and have all the requisite equipment, you really need a good finish carpenter.

Also think about WHY you are installing crown molding. Does it work with your house's style? If you have a Colonial or Cape, it probably is appropriate. It would not be appropriate in a ranch or split level, or a modern home with vaulted ceilings.

What type of crown are you talking about? There are many styles of crown molding, some more detailed than others. Some have dentil detailing, some egg and dart, some have beading. Some are plain. Some are just one piece, others are built up with 3 or 4 pieces. What works in your home?

Think about proportion as well. The size needs to be in proportion to the ceiling height. You don't want a skimpy one-piece 2 1/2 inch crown on 10' ceilings.

Do you have it in other rooms? You want it in your living room. Do you have it in the adjoining rooms, like the foyer, hallways, dining room? Having it in one room but nowhere else also would be weird.

We replaced simple picture moldings with 4-piece crowns in our living and dining rooms. Our home is a Colonial revival and the crowns work with the style of the home. We hired a very talented finish carpenter to do the work but even so, there was a lot of planning prior to the installation. This seems to be a case of you don't know what you don't know if you have to ask.

The cuts for the corners are what requires real skill. The angles are not 45 degrees they are complex angles and are further complicated if your drywall corners are not perfect.

Do you know how to do scarf joints? Cope corners? Know why a vaulted ceiling is a nope for crown? This isnt YouTubeable DIY without a willingness to ruin a lot of expensive material.

As for me..it is DIY job. I did it in our house addition.

It depends on your patience. Crown molding requires very precise compound miter cuts that are a nightmare if your walls aren't perfectly square. If you haven't done much finish carpentry, hiring a pro will save you a lot of wasted material.

Vaulted ceiling "nope for crown"? Nah: https://www.youtube.com/watch?v=iZew8T0cLjQ

In most of my DIY experiences, I have learned how cost effective it would have been to hire someone to do the project, but the experience was priceless.