1. Be open to love.First of all, you have to be willing to let love in your relationship and give love back 100%.
2. Don't rush into saying "I love you." Take the time to realize what you are saying, and that it means something. Unless you feel like it is a promise, then don't say it!
3. Make sure you trust, admire, and respect the person you are with. Can you see being with him (or her) forever? Can you really talk to each other? Can you be honest with, and support, each other? Do you have meaningful conversations? Do you mean something to each other? Is the relationship exclusive, serious, long-term, mature, meaningful, loving, trustful, respectful, and so on? If the answer is yes, then you may be heading towards love.
4. Take the physical aspect of the relationship slowly as well. This will give you time to develop other aspects of your relationship. Like the verbal, psychological, mental, emotional, affectionate, and other kinds of intimacy / closeness that has nothing to do with the physical stuff.
5. Don't let your life completely revolve around them. Your partner will find it sexy that you have other priorities. It's a sign of self-respect.
6. If you're not yet ready to say, "I love you," try "I love it when you..." or "I love your..." instead.
* When you are comfortable with that person, open up and let that person in your life.
* Trust your instincts.
* Make time for each other.
* Spend time apart as well.
* Connect/bond--on a deeper level (than physical and other ones) with one another---let there be time for the emotional, psychological, mental, verbal, and other intimacy or closeness to grow, expand, develop, etc.