The only way to sim is sim as real as possible so that when you switch there will be minute diff (not include psychology part). And for that only Ninja sim will do, as matter of fact Ninja sim is more difficult than live.
treat it like real money,so you get a psuedo psychological pain,monitor your feelings,jubilation when winning,despair when losing,your goal is to have no feelings at all,unattainable unless your a psychopath,but all the same,you need to learn to remove your emotions from trading,these emotions influence all your trades,they are what make us sheep or part of the herd,game ,prey,make us react internally to the market ,the market doesn't care about your feelings,does not take time outs to console you or pat you on the back,it's a computer,and to compete you have to react to data only,and you should only trade the market,this psychological barrier is invisible to us,obvious to everyone around us,people accept faults in others ,makes it easier to accept that which we cannot change in ourselves,so it will be nearly impossible to overcome,most people don't,traders get it beaten out of them,or fail,this is what makes trading so difficult,try to take all your beatings in sim,take notes on how you feel,if you do,they will become repetitive over time ,it will help you see them as a boring pattern,mild ups and downs that effect your trading,but have no effect on moving the market in your favor,it may or will become easier to let go ,and trade only what you see
there is NO substitute for trading real money It's a state of mind in how you manage your financial risk & emotions on every trade. you have to jump in with both feet once your confident you have the basics down in how to trade real money is the only way to know whether trading is for you or not