Use the adverb ideally to mean "perfectly" or "preferably." Ideally, you would always be ideally positioned to get a clear view of the parade going by — and not stuck behind a tall man in a top hat.
You can start a sentence off with this word to convey the idea of "in a perfect world." For example, you might say, "Ideally, I'd be able to sleep in until at least ten every morning." The other way to use it is as a synonym for "perfectly," as in "My cat and I are ideally suited for each other" or "The vanilla ice cream complemented my apple pie."