The phrase "in some cases" is often used to indicate that something is not universal and may vary depending on specific circumstances. However, if you find yourself using this phrase too often, you may want to consider using synonyms to add variety to your writing. Some alternatives include "occasionally," "at times," "sometimes," "on occasion," "now and then," "intermittently," and "periodically." By using these synonyms, you can maintain the same meaning while subtly changing the tone and style of your writing. Varying your wording can also keep your writing fresh and engaging, which can help keep your reader's interest.