Sometimes you need a comma with participial phrases, and sometimes you don’t. A participle is a word formed from a verb which can be used as an adjective. The two types of participles are the present participle (ending ing) and the past participle (usually ending -ed, -d, -t, -en, or -n).
“Making me laugh” is a participial phrase because it starts with the participle “making.” Participial phrases can appear anywhere in a sentence.
The problem with sentence-ending participial phrases is that writers often add such a phrase as an afterthought, and they often omit a needed comma. You can’t just stick on a phrase somewhere without paying attention to punctuation. If a participial phrase comes at the end of a sentence, use a comma — unless the phrase is restrictive. When your sentence ends with a participial phrase, you need to decide if the phrase contains extra information or crucial information. If it’s added information, add a comma.
A restrictive clause is just part of a sentence that you can’t get rid of because it specifically restricts some other part of the sentence. You could say, “The boy who fell off his bike wished he had stayed home.” Here, the “who” clause is restrictive: It defines which particular boy wished he had stayed home, so you can’t delete the clause, nor do you use commas around it.
A nonrestrictive clause is something that can be left off without changing the meaning of the sentence. You can think of a nonrestrictive clause as simply additional information. Such clauses are usually surrounded by, or preceded by, commas. An example is the “which” clause in this sentence: “The lake, which lies twenty miles from the capital, is famous for its boating festival.” The “which” clause is surrounded by commas. It contains additional information that is not necessary to understand the sentence, so you can delete the clause if you want.
It can be easy to get confused about restrictive and nonrestrictive elements, so remember this: If it’s extra information, use extra commas.