Set up a scavenger hunt. First leave ur house and put a clue on their phone related to a memory then call their phone. Mean while drivers the place where u will propose but when they answer the phone tell them to read the clue and get dressed in something fancy then hang up on them. Let them go to the place to find the next clue. Then make more clues for them to find until they come to the spot where u are going to propose and give them flowers and set up a picnic and chocolate and then take pictures there and say u wanted to do a photo shoot so they don’t get suspicious of u but then in a picture stop and say wait. Get down on one knee and pop the question. Your welcome