People are going to tell you to just "keep it natural" or "don't just make it look natural, be natural", etc. Which of course is true. But not really helpful.
I'd say have a blend of anchor text. Don't use exact match keyword more than once if it sounds unnatural, consider long tail anchors, keep majority branded or branded+modifier, look at semantically related phrasing, etc. And don't use it in spammy context!
But, possibly more importantly, make sure that the sites that you are linking from are good quality websites. Links from 8-10 relevant-but-meh websites aren't as good as 2-3 relevant-and-awesome websites.
If you're concerned about timing, stagger them over a month. Otherwise, 8-10 in a small amount of time shouldn't matter too much as some of those pages might not even be crawled by Google for days or even weeks. All depends on the websites you're linking from.