If writers simply place one idea next to another, the relationship between those ideas may not necessarily be clear to readers. One way to make that relationship clearer is to use transitional words of phrases. Choosing such words or phrases carefully, and using them frequently, will give your writing greater coherence; your readers will be surer about what you're telling them.

To indicate more:

again, also, and, and then, besides, equally important, likewise, furthermore, moreover, another, next

To indicate result:

accordingly, consequently, therefore, hence, thus finally, in conclusion, and so

To indicate example:

especially, for example, for instance, in this way, namely, to illustrate, thus, usually

To indicate similarity:

at the same time, likewise, similarly, in like manner

To indicate concession:

no doubt, surely, granted that, I admit, after all, although this may be true, doubtless

To indicate contrast:

and yet, however, in contrast, nevertheless, on the other hand, but

To indicate reasons:

since, because, for this reason

To indicate summary/conclusion:

in brief, to sum up, finally, in conclusion, at last