I prefer scratch, but use doctored mixes sometimes, when I need 100% reliable results.
Just some recent observations...

1. You can combine mixes. I like lemon, but find the Betty Crocker lemon cake too yellow and too artificial, so I mix half lemon and half white. I do the same with the Golden mix. I weigh them and bag the remainder, clearly labelled.

2. It is REALLY worth sifting mixes. I hadn't done that til recently, and was quite horrified by how many hard lumps there were. Everything mixed up so nicely after that.

3. I have started using butter instead of oil, as I don't like the stickiness of the cake top you get with oil. The butter needs to be softened first (maybe melted?) to avoid lumps of butter in your batter.

Anyway, that's all. Hope it helps someone!

good tips, thanks. I agree totally with sifting the boxed mix - it makes a huge difference.