Materials and tools that you will need:
Fresh birch leaves, a sharp knife and a young birch sapling to tie your whisk with.
How to tie the whisk:
Start by gathering a nice bunch of fresh and healthy birch leaves. If there are no birches in your area, you can also use willow or rowan (the downside being that you will miss out on the wonderful birch aroma). Make sure you choose beaches that are leafy all the way to the top, or else it might hurt once you use the whisk.
Choose your favorite branches, just enough that you can hold them with one hand. Then clean the bottom of the branches from leaves and small twigs, so that you will be able to tie it all neatly together.
Put the largest branches in the middle of your whisk, and use smaller once around them, to create a nice round shape to you Vihta. To tie the whisk, you need a young birch twig the thickness of a pencil. Bend it once, and then put the head of the twig, sharpened with a knife, through the handle and leave the leaf end among the branches. To secure the binding, wrap the twig twice around the handle of your whisk, and then lock it by putting the sharp end under the rounds.
Before using a whisk, you can soften it by putting it in warm water. After using it, hang it upside down to dry - that way you can reuse it again and again!