although + [clause], [clause]
[sentence]. However, [sentence].
despite + [noun/verb-ing], [clause]
These words do the same job as but: the second idea is a surprise after the first. Each one fits into the sentence in a different way.
Although is followed by a subject and a verb. It joins two parts of one sentence, and it can come first or in the middle. Even though is stronger. In speech, people often say though.
However connects a new sentence to the one before. It usually comes at the start, with a comma after it. It is more formal than but and common in writing.
Despite and in spite of are followed by a noun or an -ing form, never by a subject and a verb.
To use a full clause after despite, add the fact that.