Removing and Replacing rafter tails on patio

I have a wood patio where the tails have completely rotted and I am planning to remove and replace them. I am looking for suggestions on the best way to do this so it looks finished, yet be strong. I have read about splicing the new tails to existing in tact rafters and using either carriage bolts and or lag bolts. Won't that look marginal. I am removing the T & G roof slats, so I can get to this from above as well. Anyhow, please give me some suggestions.