For willing partners, the approach is much more fun and different. Firstly agree that whatever you do is consensual and for the pleasure of you both to enjoy. Then:
1. Read the above post and make this a part of your daily practice. As she is willing and cooperative, make her get on all fours and milk her with sufficient pressure exactly as you would a cow. Add an extra kink to it by telling her that she is really one and needs to be milked.
2. Normalise the regular use of breast pumps. Ideally two but you can buy one and alternate every 15 mins or so. The setting should be on high. Remember to coat her nipples with cream before use to prevent soreness. We want pleasure, not pain. And don't forget the nipple to clit connection, it will be highly arousing for her and encourage her to show you while she does it and talk dirty. This helps them stiffen within the pump and puts maximum pressure on the skin to stretch.
3. But nipple suction cups that are discreet but effective. You can order all of these easily online. Encourage her to wear these constantly throughout the day so that not a moment is wasted when her nipples aren't being stretched.
4. This is going slightly into BDSM territory, but get her used to (if you can) tying up her nipples with string. There is a great pic showing the effects of this below. You should not be so extreme at first but encourage her to sleep with rubber bands tied not too tightly around each nipple. This will initially arouse her and engorge them, while the bands will ensure they stay that way. In time, move onto using twine that is non abrasive and remember to use oil not to cause discomfort. Pain is your enemy and if it makes her uncomfortable, she may go off the idea. Start with one loop, then two, then three. Just the tip of her nipple should be protruding. This is highly effective.
5. For those into Lactation, tell your wife to go to bed doctor or a discreet clinic and say that you are planning to adopt a child and wish to breastfeed. They will prescribe a 100% safe and natural hormone supplement that is naturally produced within their bodies. The only difference is that high levels of these hormones only occur when the body is pregnant, therefore her tits will begin preparing for the process immediately. Never force or hurt or squeeze too hard. One or two drops to begin with is a success. Continue and she will be producing a good quantity for you to enjoy.
6. Last of all, do not underestimate the power of sucking hard and pulling at her nipples while having sex.
Do the above and see the results. I apologise for not responding to individual mails but there are too many and I like to be as detailed as possible.
Here are a few great nipples to inspire you and wank over. You can show your wife and pretend to be shocked saying that a colleague at work mass mailed this out by mistake. Tell her that they look kind of arousing and how nice it would be if she had the same. Never forget that a wife who wants to please her man will go the extra mile. A great and safe idea to introduce her to the kink. Enjoy the pics, happy wanking and take note of the twine technique in particular. Love to all.