1. Theme consistency: The conjunction should be consistent with the theme of the preceding and following paragraphs. For example, if you are discussing two related topics, you can use conjunctions, such as "besides" and "however".

2. Logical relationship: conjunctions should show the logical relationship between the preceding and following sentences. For example, words such as "so", "so" and "because" can indicate causal relationship, while words such as "but" and "although" indicate turning relationship.

3. Sentence length: If the sentence length is quite different, you may need to use some transitional words, such as "first", "second" and "last".

4. Context: It is also important to consider the context and the tone of the context. For example, formal academic papers usually use more formal conjunctions, while informal writing can use more colloquial conjunctions.

5. avoid repetition: try to avoid using the same conjunctions in the same paragraph, which will make the article look boring.

6. Consistency: The habit of using conjunctions consistently throughout the article will make it easier for readers to understand your ideas.