One simple technique that I have discovered using only my hands that simulates the feeling of vagina lips is as follows:
Make a "v" or peace sign with your index and middle fingers of one hand and slide them over the base of your penis, so that your penis is in-between your fingers and your fingers are pointed towards your toes while stroking your penis with the other hand. For extra pleasure you can stroke and move your "v" in sync with your other hand moving up and down just as a vagina.
Be sure to vary the pressure between your fingers and swirl and rotate in ways that even a real vagina can't, and use plenty of KY liquid..it's the best for lubrication. If you close your eyes you'll swear that you are having sex with someone.
Also, I have found that inserting things into my anus lubricated with ky jelly is super-fantastic...so much so that I do it everyday before I shower in the mornings, and in the evening too! I personally think that a shampoo bottle works the best, because you can wash it off in the shower, and you take it in the shower with you anyways, but any type of plastic bottle will work fine. I started with small shampoo bottles, and I have worked my way up to bottles 3" in diameter! Make sure to insert the bottle from the bottom end, and make sure the bottom is smooth and a little rounded. Its the best feeling! I can't decide which is better, masturbating or doing my shampoo bottle. You will want to come while sitting on your bottle too.
Its an awesome sensation, and I promise you will feel excellent after doing this.