A couple years ago, I did an easy but interesting experiment about the human subconscious; all you need are some data tables, a bowl of M&Ms (or variously colored candies), and lots of participants. The claim for this experiment is that people's subconscious influences their choices: for example, their favorite color of candy influences which color candy they pick).
1. Put the M&Ms in a bowl, and make sure when you call people up to do the experiment, you call them separately so the others aren't consciously affected.
2. Call up a participant (note their age and gender: it's always important to do this in any survey, and maybe you can use this to support some claims about trends you find).
3. Ask them to pick an M&M. Don't tell them anything else until they pick one.
4. Note the color they picked and THEN ask what their favorite color M&M is. (In my experiment, I found that the color they picked and their favorite candy color often lined up!)
5. Do this with many participants, and make sure they aren't aware of what they're about to do or about to be asked before they walk in the room, because every little thing can affect their subconscious.
6. I would recommend making several separate graphs with your data. For example, I made a bar graph for people whose favorite candy color was green: the x-axis has all the possible M&M colors, the y-axis was the amount of people. I found that in the my-favorite-color-is-green graph, the highest bar, or color chosen the most by people, was in fact green! (I recommend if you're printing the graphs in color, make them correspond to what color they represent: this makes your experiment really put together.)
7. If you had any other claims, like "I thought females would pick green, red, and blue the most," show how that actually played out in your data by making more graphs, like showing what females actually picked the most. (If you do this, I recommend choosing age or gender.)
8. When you put your findings together, if you're using a poster or something, put pictures and as many visual aids as you can: this makes your project easier to understand to outsiders.
I have my entire experiment and lab written up: if you choose this project, feel free to message me: I'm happy to help! I hope this was clear enough: it's easier than it sounds, I promise :)