Practice, practice, practice.
Contesting may not be one of your favorite parts of amateur radio, but it can be useful to hone your amateur radio skills in case of emergency.
Breaking a pile-up when the station you’re calling is very weak can be good practice for when the SHTF. Listening through the atmospheric noise and fading propagation can be mind bogeling. Trying to pull out that weak station in all that noise takes practice. It’s just not how most people “hear”.
Another good skill to practice with contesting is logging your contacts. Keeping an accurate record of stations you contact is important in both contesting and emergency communications.
If your preps includes a radio, you had better know how to use it.
You may think that hand-held amateur radio will help you in a pinch. But, if you’re not comfortable using the controls on the radio and don’t really know ‘where’ to find contacts, it’s going to be pretty worthless to you.
Now, granted, your antenna is critical in your ability to communicate farther. Those, too, can be practiced during a contest or special event.