I use a very simple version of function point analysis. Write down all the different things you know you need to do, beside each one write easy, medium or hard. easy takes 0.5 to 1 day, medium 2-3 days, hard 3-5 days. If you think any bits are very hard then break it down - if you can't then you've found something you don't know - and you have to focus on that - this is a risk and flag it as such.
If it's a big project then chop it up into deliverables, so you can monitor your estimates along the way.
..there's a lot more but something to get you started.
(if you have to deliver on your estimate - double it :-). When you double your estimate - make sure you don't work to your doubled estimates - otherwise you'll have to double it again :-) )
If it's a big project then chop it up into deliverables, so you can monitor your estimates along the way.
..there's a lot more but something to get you started.
(if you have to deliver on your estimate - double it :-). When you double your estimate - make sure you don't work to your doubled estimates - otherwise you'll have to double it again :-) )