Just try to get as near as possible to the natural racing posture, like being in a real-life race car. Sitting room chesterfields, different benches, chaise-lounges and secretaries will not do the work like an authentic car game racing simulator seat will.
The true driving environment is nowhere near to the abovementioned household divans, seats, writing tables and counters, isn't it? So, at least you should try to have the proper racing position. If you do not, you will not be able to detect the actual potential and pleasure the modern racing car video games are bestowing. It's as simple as that.