It's a complicated business. More than anything I'm very honest about the uncertainty these days. I also try to give ranges for things - instead of saying it will take about 2 days (which cements a specific deadline), say, 2 - 4 days.
As you get older (more experienced) you become less concerned with overestimation. When you're young and ambitious you think that a) you can do it faster than you really can and b) it's bad to say it'll take 2 days when really you think you can do it in 1. a) you can't and b) people don't normally question your overestimates.
Also, try to think things through. Ask questions. Discover those subtle missing requirements that haven't been communicated yet. Try to picture how it will fit into the system and imagine why that might go wrong. If it's a bigger feature break it into parts and (over)estimate each of those.
Be thoughtful, overestimate and be honest (especially with yourself).
Comments
It's a complicated business. More than anything I'm very honest about the uncertainty these days. I also try to give ranges for things - instead of saying it will take about 2 days (which cements a specific deadline), say, 2 - 4 days.
As you get older (more experienced) you become less concerned with overestimation. When you're young and ambitious you think that a) you can do it faster than you really can and b) it's bad to say it'll take 2 days when really you think you can do it in 1. a) you can't and b) people don't normally question your overestimates.
Also, try to think things through. Ask questions. Discover those subtle missing requirements that haven't been communicated yet. Try to picture how it will fit into the system and imagine why that might go wrong. If it's a bigger feature break it into parts and (over)estimate each of those.
Be thoughtful, overestimate and be honest (especially with yourself).