And if you are not in base , as already someone said : a campfire when you are alone and sit : you get a free 8 mins rested buff , 11 mins if was in a place with roof

This may help you.

https://valheim.fandom.com/wiki/Food

Getting your main sleeping area rested bonus up early is key here.

When I start a new game I always knock trees into birch for finewood. First thing I make is a finewood chair and table. Deer carpet. Raspberry banner.

The rested buff from that stuff on top of the bed/fire/cover should last you all day.

use a good meal combo along with the well rested buff with the duration depending of the comfort level of your base you have also stamina potion and mead that temporary buff your stamina regeneration and you have a boss power that reduce your stamina usage

Subjective. Well-rested basically need a campfire with no enemies around at the minimum. Place the campfire, sit near with X, wait a little bit, get the buff. Another minute from finding or building any shelter (just anything that works as a roof over your head). Another minute from having a bed nearby. You get the point. It is not really that annoying, and it makes sense that you need to rest now and then to perform better.