How to get a customer to leave their size request

[GrowingUpWild]

I have REALLY hard time getting customers to leave their size request at checkout. Each of my listings says something like:

When you order in message to seller please specify:
1)Size
2)white fleece or chocolate brown cotton lining
3)Sole (eco felt made from 100 % post consumer recycled plastic bottles for non-walkers, or suede for walkers)

I have had three orders this week however where the buyer did not indicate a size. I send convos but it delays my processing time and I am afraid they will be expecting their package sooner. Buyers don't necessarily check their Etsy several times a day the way that sellers tend to!

How do you make size selection easier for your customers?

[Former_Member]

I would spell it out like a catalog does in capital letters SM, MED. LGE or the nos. not just the word size. Your shop/product must be amazing if the customer doesn't even slow down to give you their sizes.