All you really need to do is get inland, and usually not very far.

In this sample evacuation map for Ocean City WA, the higher ground is within half a mile of a good chunk of the coast, and nearly all of the coast is a mile from higher ground. https://www.dnr.wa.gov/Publications/ger_tsunami_evac_oceanci...

All along the Oregon coast are signs indicating where the tsunami impact zone is, and I think there are also alarms in a lot of towns too.