Our coding standards call for _fieldName (i.e. lowerCamelCase prefixed with an underscore). I've got the underscore configured correctly in ReSharper|Options.
What I'd like is a live template macro called something like "Suggest field name based on ", which basically does the correct capitalisation and sticks the configured prefix and suffix on that name.
At the moment, I have to use _$fieldName$, and have fieldName defined as "Value of propertyName with the first character in lower case". This is excellent, but it could be even better.