I normally don't. I believe that the historical use of runes as symbols has led to a magical association of concepts to the runes. I could theoretically use any set of symbols with an occult tradition. But that's simply a personal belief and doesn't have to apply to anyone else.
I usually use my personal ability to channel magic and ambient magic around me to power runes. However I have invoked Freyja before. I cast a spell relating to love and I trusted the goddess of it to carry out the spell in a proper fashion and decide if it's just to cast in the first place. A goddess on your side also greatly boosts the power of a spell (no duh). Maybe my experience with her will be helpful to you.
When I invited her and only her to come to my circle, I was very surprised. As an entity Freyja did not give off a sense of love or lust. She is alien and produces and aura nothing like a humans. It is metallic and yet formless, colorless while making everything else bland in comparison. I am sure she can be a goddess of anything she chooses. I explained my spell and how it worked and why I desired it. I can't tell for sure but she felt patiently intriqued to me. I had the sense that she meant me no harm but when I finished my spell I had a feeling of her encompassing me and smothering my will until the moment I gave her my promised offering (a pink folded paper heart smothered in honey and left in nature), then I felt a deep sense of amusement and pleased indulgence out of nowhere.
I desired a summer romance, being too young and about to go through too many changes to have an enduring relationship. I wanted to a attract a partner who would improve my life through meeting me and whose life would be improved in turn. The spell worked, and it gave me not a little happiness.
That's my experience with the divine, I hope it helps.