We've seen how a good and positive hand shake is exercised. It's time to know that which things need to be avoided to retain positive impression that hand shake builds. Avoidable things mentioned below negatively affect the very basic purpose of this ritual - expression of openness, cooperativeness, enthusiasm, and harmless state. Charge yourself with faith and self-esteem before engaging in hand shake.
Do not touch, scratch, pinch or rub any parts of your own body; it could invite irritation from other side. If you engage in hand shake first time with other person, it's very important not to touch his/her body parts also. Don't put free hand in pockets or hold it behind your back because it communicates lack of enthusiasm or suspicion. Don't exercise hand shake with gloves put on as much as possible. Don't put free hand on hips; it's sign of domination. Don't point at any direction by free hand; it communicates disorientation.
Don't point by fingers at person engaged in hand shaking, it's invading. Don't keep any objects between you and other person like chair, table, file, folder, cup, mug etc. Don't shake hand over the walls, roofs or partitions if possible. Don't look downward or upward after a hand shake. Simply give brief glance at the eye level to either side and return gaze to other person with smile. Don't cross hands over chest after a hand shake. Exchange some good words with open and empty palm of other hand facing upwards.
Most important thing is not to exercise hand shake every now and then during interaction or while being introduced. It simply communicates that you're imposing yourself on the other person or want to get more out of the deal. In few cultures, it's permissible to exercise a hand shake frequently. Almost globally, hand shake at the beginning and at the end of interaction is a normal practice.
Generally, women don't offer a hand shake on their own in most societies and cultures.
After rapport between you and other person gets established, it's positive move to briefly touch his/her wrist, elbow or shoulder to express trust and to boost union. This would help to reduce formality and to promote friendliness between individuals who are familiar with other. It should be exercised between equal ranking personals or should be offered seniors to sub-ordinates.