I found this great site which has advice from writers, starting with some tips from V S Naipaul. Naipaul recommends short 10 word sentences and small 5 lettered words:
1. Do not write long sentences.
2. Each sentence should make a clear statement.
4.Never use words whose meaning you are not sure of.
5.The beginner should avoid using adjectives, except those of colour, size and number.