Hello!!
Are you also interested in taking a close look 
at the “tiny” world?
If yes, then you are at the right place!
I did an experiment, in which I used a tiny convex lens which I found in an old toy watch…you can simply get it from a store or find it in a laser pointer.
So, let’s get into it!
Materials Needed
︎Small Covex lens
︎A cardstock paper piece [4 x 2.5]cm
︎A pair of scissors 
︎A smartphone [Here, I used Gal*xy A21s]
︎Smartphone back cover or Scotch Tape
Method
STEP 1: Cut out a hole in the centre of the cardstock. [The hole should be bit smaller than the exact size of the lens, so that it fits in nice and fine
STEP 2: Now your lens mount is ready, so fit it on the closeup camera of your phone with the help of Tape. You can also simply tuck it in the phone cover.16338484649003203773209958244642|666x500
Turn on the camera’s flash and put your camera on Macro mode, in some phones, a single camera may even work in multiple modes.
Your, closeup camera is ready!!
Now, place the camera 1-2 cm away from the object and click the shutter!
I clicked many pics with this method and they turned out really good! 
Take a look at them…my favorite ones are the Housefly, Spider & the Algae…
Optional Work
If you want this type of effect in your pics 
Then, just cut a 7mm piece from a pen cap and stick the lens on it…then do the same from STEP 1.
You can take help from the following
Hope you enjoyed!