Yes you vibrate each letter, the power of the runes is in the vibration, please read here:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/Runic_Pronunciation.html
Also here to see what is the power of each rune:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/Odin.html#ODHAL
Also use their specific number which is the order that they are arranged, FEHU is the first so it can be used as a multiple of one (1,2,3) while ÖDHAL is the last so it's best to use with a multiple of number 24 (24, 48,72)
The way you use them it depends, let's say you want to improve yourself, you check out the SS calendar and see what dates are the best to make the most out of it's power, of course you can use any other day as long as it's not on the void course of the moon.
Also don't forget about the colors:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/Color.html
Here is an example with FEHU that it helps to brings money.
You start with vibrating FEHU into yourself through your imagination.
FFFFF-EEEEE-HHHHH-UUUU (do this by a certain number) let's say 40.
Then choose an affirmation that it's in the present, only present.
vibrate AUM
''I attracting big sums of money in a very healthy and positive way for me'' (a cheap example, some could give you a better affirmation).
vibrate AUM
Do this 9 times.
Congratz you used a rune, of course you can use it without affirmations like a normal meditation, also intention matters a lot.