Sure, it's possible to write long, complex sentences, and sure, these sentences can often look artful and impressive. But, to be honest, you're looking at these tips because you have difficulty communicating successfully in writing. Such complicated sentences are challenging to write and are, in fact, minefields of difficult constructions. Avoid them.

Sentences should be simple and have exactly one topic. Two topics get two sentences, three at least three, and so on. Don't say "our new widget will save users at least $47 over the life of the product, and they will also have an easier time frombulating with that." Instead, try "our new widget will save users at least $47 over that widget's useful life. In addition, the new widget makes frombulation easy." No challenge being clear there, no question what point the user should take away. Sure, it's simpler, but it's much easier to write well, and good writing makes for easy communicating, and easy communicating will lead to success.