I share your pain having failed it 5 times now (twice with Pearson & 3 times with IELTS). You don't say whether you are in Oz or UK, but I sense a fairer marking system is operating in the UK with Australia using it either as a cash cow or an immigration choke point, or both.
Being an ex-pat, it's easy to get complacent. And maybe I was in the early days but now it's just becoming a joke. I'm 44 years of age and now find myself watching helpful clips on youtube to see where I'm going wrong. I passed my English Lang & Lit with flying colours nearly 30 years ago, back in the day when O levels set the bar a little higher.
Vanduex is right, form a structured & intelligent response .. intro, middle & conclusion. There are many sources of info out there, this being a good site ... http://ielts-simon.com/
From reading around, you may find that the General module is slightly easier. I was scoring top marks with Pearson on everything bar speaking (7.5) & I've no idea where that was going wrong.
IELTS ... Had a disastrous day initially with listening (if you lose the thread or can't quite grasp the context then you get left behind and you've had it, fail). You have to be 100% focused on the listening. Since then, I've also struggled with writing, achieving 0.5 point under the 8 I require. Fair to say, it's grinding me down now. I've got no idea who is marking these papers but I would like a face to face with them to see exactly what it is that they have a problem with. Maybe they see an English face and want you to fail, I don't know, but that's what it's looking like. There aren't many Aussies I know who could pass this test so what does that tell you ... that they should all be deported from their homeland?
Let me know how you go & happy to talk offline. Cheers, Chris