Hooks can be sharpened to a point and forced through the skin, although this is unnecessarily painful and traumatic. The most common and practical means of insertion is to first make the hole with a standard piercing needle and follow that through with the hook.Needle and hook are usually in the same size, but that is entirely optional. If a larger needle is used (for example, a 6ga piercing needle followed by an 8ga hook) there will be additional bleeding. If a smaller needle is used, the hooks may be tighter and be a bit sorer prior to suspension.
It is essential to maintain a proper set up to avoid risks of contamination of the fresh piercings and of the equipment - this should be a top priority. Many suspension crews choose to set up an assembly line where one person pierces and inserts the hooks, and another preps the rigging system so that it's more difficult to contaminate the framework.