I think the favourite part of my poorly paid and probably soon to be non existent job (go go LSC and CLAN's) is helping clients who come in with notices from their landlord. I hesitate to use the word notice as they seem to take all sorts of rather strange forms.
Most of the tenants I see are statutory periodic assured shorthold tenants. Amusing mistakes (yes my job IS that dull) range from the common section 21 4a 'I require possession on X date' rather than after X date fatality to 'here is your 4 weeks notice to quit I'll be around on X date to pick up the keys'.
By far the best was a landlord who made the same mistake (requiring possession after X date where X date was in fact 1 day to late) TWICE. Having been to Court they proceeded to do the same thing again. They spent about a year trying to get rid of their tenant :).
I do actually feel sorry for you landlords who decide not to get any sort of legal advice before issuing a notice but I have to say thank you for brightening up my day.