I know we all wish we could have plenty of time to scrap -- but usually that is not the case. Here is a tip that can save you a bit of time.
When I started scrapping I picked up this tip and it is one that is super helpful. With cardstock cut the most popular size photos that you tend to use. Cutting more that one of each size is helpful as well. These can help you when you are putting a page together and are not quite sure how big or small you may want the pictures. And even if you don't print at home this can also help you figure out what size photos you may want to order.
I keep these within reach so that if I want to add more photos I can easily decide which size. Hope this was helpful!