Invading the male mindset for a while, just nake sure he's the right person before you attempt this. Make sure you're not infatuated and that person is treating you right.
Explore the possibility of your boyfriend proposing to you. Make yourself worth being proposed. Increase your chances of getting "yes" as an answer by increasing the bond of your relationship. Start treating him like a husband. Let him feel the warmth and care you have to shower. Before you know it he'll be down on his kneels with the ring or if not, you can propose without fear of rejection.
Try to learn about his feelings. Some men still believe it's so weird for women to propose.
Understand why your boyfriend don't seem to care about going further. The number one reason why men delay proposal is lack of stable income. If that's the case, support him to reach his dream instead of the proposal. Focus on the future and let him recognize that. Show him you can help and practically do your best.
The proposal...
Prepare for it..the way you want to. May be romantic. May be cocky. May be official. May be diplomatic. May be celebrative.
Choose a suitable locations based on your likes. It doesn't always have to be unusual.
Your character should be normal let your feelings guide your expression. You don't have to be a movie star. Listen to your feelings and pour your heart. You don't need to do the ring or flower things. Remember he's a man!
Be brief and nice. Few but passionate. Geniune and expectant. Look him in the eye, not stare. Do not be shy, only nervous--natural feeling.
Do not push yourself to it. If for any reason you're losing your confidence the day you want to propose, stop and reflect. Let your confidence decide.
After: if it's yes, celebrate with a planned occasion. If he says no, celebrate by maintaining a mood of grace and acceptance.
