To become a healer, the Sigrdrífumál advises carving runes on a tree whose branches face eastward.
In the Hárbarðsljóð, Thor returns from fighting jötnar in the east; facing the runes east towards Jötunheimr may have been believed to subdue evil forces.

“Brimrúnar skaltu rísta, ef þú vilt borgit hafa
á sundi seglmörum;
á stafni skal rísta ok á stjórnarblaði
ok leggja eld í ár, er-a svá brattr breki
né svá bláar unnir, þó kemstu heill af hafi.”

“Branch-runes learn, if a healer wouldst be,
And cure for wounds wouldst work;
On the bark shalt thou write, and on trees that be
With boughs to the eastward bent.”
~Sigrdrífumál 10, Bellows

Painting: Thor, Hymir and the Midgard Serpent by Lorenz Frølich, 1906. 𐘾