Don't listen to your friend. Or if you do, because they are your friend, come back and ask us. One can only generally go into the state of mind your friend is referring to after many years of intense meditational practice and a strict ascetic lifestyle. What he should have said is that relaxing the mind and body would be highly beneficial in your efforts.

Firstly with WBTB it is just that. You go back to sleep an hour after waking from 6 hours of night time sleep. Relaxation would help you go back to sleep.

Secondly relaxation is very important if you want to have consistent success with WILD's

FILD - Can't answer you there as I haven't looked into it deeply enough to give you an answer.

Trust me. Relaxation is very easy. When doing your inductions just pretend you aren't going to do any lucid induction techniques and pretend you are just going to sleep as normal. That is an excellent relaxation exercise as its the most natural one there is given to you by nature.