i had a LD the other night (my second succesful attempt!! 
) and i used the rubbing hands technique to calm myself and stay lucid after i relised i was dreaming, i also yelled “INCREASE LUCIDITY NOW!!!”. This worked and the dream was clear and bright.
I was walking down a forest path and i said when i turned the next corner i would meet someone who could guide me. I did meet this person, sadly i was no longer lucid once i started talking to him. 
i dont recall losing my lucidness, my dream just carried on as a ND.
How can i ensure that my lucidity lasts???
Levitate around. If you ever forget you’re dreaming, when you notice you’re dreaming you will remember!
First thing I always do is levitate or fly when I become lucid.
I, thankfully, never have any occasions where I lost lucidity. (Although I used to a lot. ) However, what I do to ensure I will remember I’m dreaming is. . .Well, anything that couldn’t be done in reality! Like Darxide said, fly or levitate, you won’t lose lucidity if you are doing that! And also, you might want to try reminding yourself calmly that you are in a dream once in a while; this way you won’t startle yourself. 
That “Increase lucidity now!” command usually works. 