If you are looking to boost your Lexical Resource (25% of the IDP marking criteria!), then check out this tutorial all about GMAT vocabulary.
Sample GMAT essays for GMAT writing task 2 two can be found here, and sample letters for the general module can be found on this page.
If you are looking for help on how to start GMAT Writing Task 2 – there is a valuable video in this post.
NEED TO PASS GMAT FAST? Or just tired of taking the exam too many times? Have a look at this special online course that helps you improve both your GMAT exam skills and English language skills.
Alternatively, you may just need to work on your grammatical range and accuracy, so an essay correction will help you identify your errors so you don’t make them again. This site offers economical essay corrections.