As mentioned in a previous thread I think checklists are a good idea BUT if single pilot then only if you can 'afford' to be hands off and then only if it's something that can't be learnt 110%.
I always use checklist for pre-start/start and will use it for preflight too if not flown type recently... covering my backside maybe? I have made my own, laminated for the types I fly, based on the manufactures' checklist/POH but in a more logical manner for the preflight to save jumping in and out of cockpit and from side to side.
But if you have an in flight emergency in single pilot helicopter I think you should/must KNOW instinctively what to do - its enough fun trying to map read/navigate etc in something like the R22, wouldn't want to try using an emergency step by step list.
I don't fly anything complex so maybe its different for a more stable or twin machine?
PW