I use timing too. I started when DS was about 4 months old, and we do EC part-time.
It's quite possible that he shows signs of wanting to go but I just miss them - I'm not very intuitive. My husband can sometimes predict a poop and say "he just has that look" and I"m oblivious! Yet we've managed to do pretty well with the EC anyway.
Like others have said, is there a time when your daughter pees a lot? For my son it's in the morning - he'll pee quite frequently in the first couple of hours. So that's when I started offering the potty, simply because it upped the chances of catching a pee and being able to cheer and let him know it was a good thing. He caught on VERY quickly, and I would think that at 8 months it would be even quicker.
Because I made the decision that we are part-time ECers and use diapers as backup almost always, I don't even think of wet diapers as "misses". I change my son hourly - I need to anyway because he has very sensitive skin - and I just offer the potty at that time. Some days we go through 2 diapers with lots of pees on the potty, and other days I get the timing wrong and he has quite a lot of wet diapers. On some days I'll even catch a dry diaper when we're out and about, and he'll now pee in a public toilet!
You may want to consider whether you want to use a potty or a toilet seat. We use a toilet seat because my son is quite large and because, well, I hate cleaning potties. It works really well. But won't be as convenient when I want him to take himself!