How can i create a presentation of a group ? in Dummit and Foote , the notion of presentation is introduced in section 1.2 which talks about dihedrial group of order $2n$. 
and after this , it was rare to talks about presentation throw the exercises or the material of the sections . but suddenly in chapter 4 , it asks to create or make a presentation of particular groups , and i don't know the right methods and strategies - if any exists ! - which i can follow 
so , any help with that ? i think that presentations and relations play fundamental role in the advanced levels of the study of group theory , so it's good to develop my skills with it from now and on  " just a feeling ! am i wrong ? " 
 A: There is no general strategy that you can follow to obtain a short presentation for a given group. Some things to look for are elements of particular orders that you can easily identify in the group. If you have an element of order $k$, then add a generator $g$ and a the relation $g^k=e$. Next, among such elements, or powers of such elements, look for conjugation relations and similar things. That is, suppose you have two generators $g,h$ in your presentation and you want these to correspond to two elements in the group that you have. Then check for their orders and the way the multiply with each other and with powers of each others. Among these try to find those that look like the most important ones (those from which the others follow). For small groups this will soon enough lead to a presentation after enough trial and error and your intuition will improve. However, this presentation may be shortened by noticing that some relations are redundant as well as by choosing different generators. 
