Honestly I think the best we can do is invest heavily in the academy and buy the cliche "best of the rest players" hopefully (and with luck) then we progress.
Should we get champions league we would then struggle to sign the players capable of progressing us further or even consolidate that position as they want a team who get in it every season/challenge for titles, champions league doesn't magically make a flood of top players want to sign for you.
We don't have the name like United and Arsenal do or the uber wealth like Chelsea and City so we can't attract high calibre players, we have to try to develop them and keep them around for long enough to actually achieve something.