Again, this is just how I Rick Berg, as a reader of comics, usually read comic storylines that are to span multiple comic book titles. This is not how you should do it or how you have to do it. This is not how Rick Berg as a retailer, wants you to do it, that guy wants you to buy all of them and all the covers. This is just how I try to do it for myself. You can do it however you like.
Let’s start with the announcement. Say CREATIVE ENIEBRIATIONS announces an event called BLOODEAGLE THE DEATH OF THE WORLD. 
Do I like/ read CREATIVE ENIEBRIATIONS as a company?
No! Then I stop paying attention until a creator name or character I usually enjoy is mentioned at a later date.
Yes! I look for further info. I look to see what type of event it is. Is it 1 separate mini-series? Does it only crossover between 2 books? A combination of both? Something else entirely? I only have so much time, money, interest for certain things. The last thing I need is another event book to waste time on. I always will have my regular comics to read. I am years behind on TV I want to watch. There are video games, raising my kids and toys to play with.
Anyway, CREATIVE ENIEBRIATIONS has a lot of talent I enjoy and an entire slew of comics I like to read. So, if I have to jump on a few extra books that’s usually fine by me. Usually, sometimes I just don’t care about symbiotes or zombies or leather jackets with chains. Might be a cool action figure but is not a cool comic to read.
I check to see which creators are working the books because for me, if a talent I enjoy is working on a character I don’t care about I still may want to read it. I have read every Mike Mignola book I can get my hands on. Whereas I don’t necessarily read every book that my favorite characters are in. I can barely stand Jason Aaron’s Avengers run with Thor by Jason Aaron being one of my favorite comics ever. Having read comics for 40 plus years, I have read enough crummy Thor stories to last the rest of my life. If you need every appearance of Dr. Bong? Go for it. I do not.
At this point It is pretty easy of me to decide. Talent I like? Yes. Characters I like? Yes. Then I’m going to read the main book. If there are supplemental mini-series to the main book, I almost never read those. Unless those feature talent or characters I like. I have yet to read or miss a story or even plot that was important to my understanding the main story.
I really truly do not give two poops about GwenPool, so why would I ever read War of Asgard Gwenpool by TBD and NYA. Yet, if the mini-series is written by Kevin Birtcher with art by John Deberge? Then I will read those extra issues. Sounds good to me. Both those guys have a proven track record with me.
If the event is numbered #1 -22? Then I will try to read all 22 parts. After 3 or 4 parts it is very evident whether you really need to read all 22 parts or if it is just 2 pages an issue. 2 pages usually does not matter to the main story. I can not remember a tie-in book that only had 2 pages of INDUSTRIAL WASTE that was so important to buy an extra book. I have found most of the time that when books are numbered that they are actually all important to the main overall story. Or at the very least continue the story from the previous part to the next.
I also want to point out that after 3 or 4 issues of not good? I will be done with the crossover. Hell with 99% of books I will quit them. Personally. (Retailer Rick usually keeps reading for a few more issues just to stay informed of things).
In the end? Read what you think you will like. Don’t read Aquaman #14 just to see if he wears goggles in the War of the Goggle King. You don’t like Aquaman? Then don’t read it. I guarantee that you will never ever run out of things to read without having to read 2 pages of Aquaman trying on a pair of fish encrusted goggles because VEGGINGHOT.COM said it’s the best book ever. If it was something you like, you would most likely already be reading it. You can’t and don’t need to like/read/know everything. But if it looks cool to you? Then by all means pick up Aquaman #14.It just may lead you into needing the previous 13 issues of the greatest comics ever. But I doubt it.