For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
If God so love the world, that he could pay such a supreme sacrifice for the world, it means we must live and cherish the world, don't express the love wrongly only express it in full towards the right direction.
Think of all the great moments that you have shared with someone, draw inspiration from there. If you think you won't remember, write it down or even better, make it into a poem.
Try to think of words that can describe what your feelings towards him/her are. The happiness you feel when you are around him/her and the necessity you have to being with him/her. You can make use of images videos, and good materials look around you even on this page you will find some useful stuff to send to the one you love or wish to express true love to.
Find a place where you'll be comfortable and alone.
Tell them how much you want to be with them. they will appreciate that you are showing them your love and not just saying it.
Spend as much time with them as you can.if you love some one, you should prefer always to see him/her all the time.
If you feel they have something to say, do not ignore them.
Tell someone you love that you LOVE him or her always! just say it. Don't try to think of the perfect time to say it because sometimes it will never come out, if you become too nervous. If you didn't prepare anything to say, just speak your heart out.
Use materials around here to express REAL love and find REAL love....
Cheers!