Along with the suggestions given, you could go about it a couple more ways. 1) you can simply say the name of the rune as a method to invoke it. Though this is a more modern method and is the weaker, unconventional way - per say.
2) if singing the rune like "fehu fehu fehu f f f f f f f f f fu fa fi fe fo of ef if af uf f f f f f f f f f" doesn't quite fit your fancy, you could go about it by singing the name like you would words to a song. Fffeeeeeehhhuuuuuu. Giving extended emphasis on the vowels of the name. As I said, much like dinging words to a sing.
I don't recommend speaking the name of the runes, for it is weaker and not really as it should preferably be done. The vibrations from singing the name is what you really want. This gives a more - fuller - potency when invoking.
To to add to this, there are some other methods to incorporate: holding the rune in your hand; drawing it whether that be on your body, on the ground, on paper, or painting it on a surface; and mentally visualizing the rune; all of which can be whilst you invoke the rune.