You need to organise your working day around your type. If you are a Morning type, then plan your main tasks for the beginning of the day. It will be fatal to leave important (but possibly unappealing tasks) until after lunch. The afternoon will arrive, you will look at the task and decide that “as I am a Morning type, I’ll leave this until tomorrow morning.” Taken to its logical conclusion, tomorrow never comes and you can find yourself putting the task off until it is really too late.
If you are an Evening type you should plan those important tasks for later in the day. You should also arrange your meetings at this time when you are at your most productive and most alert. Start the day with the routine tasks that don’t require a lot of brainpower. But beware of falling in to the trap of concentrating on the easy (and possibly more enjoyable) tasks throughout the whole day. This may sound simple but just take a moment to think about some of your recent working days. Have you been as productive as you should have been? If not, have you tried to address tasks at the wrong time of the day with predictable outcomes?