When I ran my half in November 2013 the longest training runs I had done were around 11 miles. The half went beautifully but I had already decided I was going to walk all the water stops. This worked beautifully -- I did all the running I had planned for and made my goal time. Since I had only been running six months of my life that was huge.
My goal this time is a fast pace, but I haven't decided what I'm going to do about walking the water stops. I probably still will -- the first half I did had very frequent water stops and I don't expect to have so many in the next one. But I'm thinking that I've got MUCH better training partners this time around AND I won't be fighting a broken heart chained to my ankle, so my running pace will be a lot stronger, which will mean a much better overall time. Another thing that will help is that I'm training in a Northern state but my next half is in February in a Southern state, so my cardio fitness will be better.
WRT to taper... I follow published training programs for that sort of thing.
Good luck y'all!!!
Me42, H40 D12, S8, S7 A revealed: 7/13 Sep 4/14; Agreed to D 1/15
