I like to do my most creative work early in the day. But that means that language work gets left until the end of the day. (By ‘work’ of course I mean ‘play’.) Anyway, by that time I’m usually a little low on energy.
That’s by no means a bad thing, as it encourages me to work lightly and quickly—skimming over things, missing stuff out and generally ‘cheating’. But overall it’s probably best to spread things out throughout the day.