It really comes down to the specific collection. Some TPB and omnibuses are more complete than others. Google is your friend in this instance. If there's a collection that catches your eye, Google around to see if there's any supplementary reading that goes with it.

Alternatively, of your have an android device and you don't mind reading your comics digitally, you can do what I do and use Mihon (https://mihon.app/) to find most comics for free and then just Google the reading order of whatever it is you're trying to to read. For example if you want to read all of Clairmont's X-Men run you'd just Google "Chris Clairmont X-Men reading order" it's that simple.

I think that - if you want to read current Marvel story arcs, but not buy every tie-in story (from characters you don't really like or care about, for example) - digital comics are how you'll want to go.

There are lots of ways to get free digital comics, and as the other reply said, use a search engine or wiki to find the reading order and all the tie-ins. That's just the way Marvel does things, and I'm pretty sure DC does it the same way - that's how the story stays cohesive, and how more sales are made. Your friend is absolutely right.

If you're going to a local comic book store, try asking the employees - not everyone cares, or pays attention, but sometimes you'll find a passionate employee (or owner) who can help you find the tpbs involved in the storylines.

With Western comics, you sort of don't. You follow specific series with the characters you like, or you obsessively compile reading order lists from various wikis and comic tracking sites that each seem to add more and more issues until you've spent way too much time and money.

Reading manga is a lot more straightforward, in my experience. You just read it in order and then check if there are any sequels or spinoffs.

I look at the issues collected in the graphic novel. Often I'm buying these quite late in the game. Standalone series are the best - it IS difficult to drop into such an established universe as Marvel or DC. I haven't run out of reading material yet, if you want suggestions.

Sometimes there is a reboot, I read Moon Knight when it got rebooted, well before the TV show, and that was easy to follow. So if you look for a series that starts at a new beginning point that works.