The non claiming way is to have a royal marriage, and then wait till their monarch dies. Hopefully, there will instead of being a regency, it going to you and making a PU
If you can maintain the PU, there is a good chance that at some point you inherit the country
HTTT makes this easier by letting you see who has weak succession claims and who is next in the line in a dynasty, etc. But I haven't played so can't give full specifics
And omg, I never realized Claiming the throne would give me a PU
:wacko: