Ethics
The Yogic Rules (Yamas and Niyamas) have a psychological purpose behind them, as well as keeping you out of prison and polishing your karma! The benefits and procedures are explained in detail in the first two chapters of The Spiritual Science of Kriya Yoga.
Abstinence or Yama
Yogis are directed to abstain from:
Injury
Lying
Stealing
Sensuality
Greed
Each abstinence should be carefully understood at the intellectual, verbal and physical levels. It is useful to develop the opposite of the quality one is trying to diminish, e.g. accuracy rather than untruth, or giving rather than taking too much.
Understand that the Spirit which assuredly pervades your Life (whether you acknowledge it or not) does also pervade all other Life (whether you acknowledge it or not). Hence, do as you would be done by!
The rule on sensuality or celibacy is often misunderstood. For most people, the path of the householder is indeed the best spiritual pathway. One of the duties of the householder is to procreate a family and give to them wisdom. The rule requires appropriate control of all the bodily organs according to circumstances. The flexibility and good sense of these principles is admirable.
Further, the rule is not just about sensual desire but any kind of major cravings. This scale of craving will scatter the mind-force and reduce one's effectiveness (and possibly cause problems for other people who don't deserve them). So, do take an inventory on your cravings, when you start working through these rules. It's your own stuff that these rules operate on. This is very real! But Rome wasn't built in a day, so take a breath.
If you don't want to be a householder you could always pursue a life as Sannyasi or monk, which is not impossible even in the West. I have met some delightful renunciates at the Sivananda Yoga Centre - they make learning truly fun.
Observance or Niyama
The Yogi is directed to observe the following:
Purity
Contentment
Austerity
Study of the Holy Texts
Attunement to God
I read the Upanishads in translation at an early age and found that much resonated for me. I think that the Attunement to the Divine is the key to the rest of this. There is nothing here to stop a person following any religion, and in fact it is positively encouraged. Austerity is particularly (but not exclusively) encouraged in Islam and by the Quakers (Religious Society of Friends). Fasting is an austerity that is part of both Islam and Christianity.
