Hi, I have been managing to attain lucid dreams recently, but they are very dark and unclear. Also as soon as I realise that they are lucid, I slip into wakefulness. I've remained calm and tried stabilising the dream by asking and shouting for it to be brighter, touching objects, rubbing my hands and concentrating on an object, but nothing seems to work. The dream just slips away.

Can anyone give me some advice on how to:
1) make the dream brighter and clearer
2) stabilise the dream

Thanks