Trying to streamline the shipping process

Hi Everyone, I'm new to shipstation and trying to figure out how best to use all of it's features to my advantage to streamline the pick/pack/ship process. I have a business with over 3000 products and they are all fairly small and inexpensive so every order is different. Our current process is this. Packing slip is printed, then packer takes slip and walk around warehouse to pick the order. The completed order is then put on a shelf for the shipper who takes the order packs it into a box or envelope and then weighs and ships it. Most of our stuff goes into bubble envelopes and goes first class but we also do a lot of priority and UPS. The down side is that we are very seasonal so when we are busy we have a lot of seasonal employees here that aren't as familiar with shipping so they are checking prices to determine what's best. The whole thing is a time consuming process and I know there's a faster way to do all of it but I'm not sure how. A lot of my competitors are doing same day shipping but We're shipping 5-6 days behind. We are also running a Magento store if that helps at all.
Any suggestions would be appreciated.

Thanks,
Jef