To save time while making the vermicelli and flavoring syrup, use store-bought falooda mix.
Chia seeds are a great substitute for basil seeds if you don't have any, as they provide a similar gelatinous feel.
Prepare the vermicelli ahead of time and freeze it in parts for quick usage as required.
For easy and reliable flavoring, have a bottle of premade rose syrup on hand.
A simple foundation is vanilla ice cream, on which you may add mix-ins or toppings for variation.