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.