Be precise with measurements of Ingredients.
The consistency of the dough is the key-point.
If your dough is too dry, puris will not puff up.
If your dough is too soft, puris will not get a nice crunch.
Do not flip puris until you get a brown crust on the first side. Otherwise, puris will lose the crunch.
Oil should be medium hot.
If your dough gets dried out, gradually add water in small quantities and knead into a soft dough.
Add one puri at a time and press it down. If you add all puris together, they will not puff up nicely.
You can roll one by one puri as well. For that pinch-out lemon size ball and roll into a round / oval puri.
If puris are thick, they will not get that nice crunch and later on will get soggy.
For perfect puris, practice it required. So Don't lose heart and keep practicing!!