If it is colloquial, I think 比較喜歡 is the best way to put it. Also you can say 偏好、偏愛 EX: 我比較喜歡溫暖的天氣，不喜歡冷天氣，(我偏好/偏愛溫暖的天氣，不喜歡冷天氣)。However, 偏好、偏愛 are more like written language (more formal). When it comes to the word 'prefer', we sometimes use sentence structure to express the meaning. Use your example sentence as an example: I prefer not to talk on the phone unless I absolutely have to In Chinese, we might say something like 若非必要，我通常不會在電話上說。 So in this case, there is no fixed way of translating the word 'prefer' coz we express the same meaning by using different sentence structure. Hope my answer helps. Good luck.

相比冷天，我更喜欢暖和天。

Prefer=較/比較 Prefer not to=比較不/較不 我比較喜歡= 我喜歡+something/someone多一點（我喜歡冷天氣多一點） But if you are comparing between two things or among more than two things. You use 更 我比較喜歡冷天氣 但我更喜歡下雪天

更/更加喜欢