Thank you for your question. Having complete concentration in every prayer is a station that takes time and much effort to arrive at. It is a journey that has many aspects to it, and it cannot be rushed. Here are a few basic aspects that can be started with:
1) know the meaning of what you are saying
2) create conditions which aid concentration such as praying in a quite place and without being in any kind of rush to do something else straight after
3) know the philosophy of why you are praying and pray out of understanding rather than routine
4) work on a natural type of concentration and do not rush to force a concentration that is solely a facet of the mind. There are other states in prayer that are the cause for absorption.
5) work on purifying the self and experiencing God's presence at all times.
6) try to not pray on a full stomach or when you need the bathroom
May you always be successful