Here are some words and phrases that you can use to help keep the relationship among sentences and ideas clear to your reader. 

Transitional Words: Coordinating

Relationship Expression
addition, continuation and, also, in addition, moreover, furthermore, first, second, again
contrast but, however, nevertheless, not withstanding, on the other hand, on the contrary, yet still
exemplification, illustration for example, as an illustration, for instance, in other words, that is, in particular
similarity similarly, likewise, in a like manner, in the same way, in a similar case
conclusion, result therefore, consequently, thus, as a result, as a consequence, then, hence