Weighing/measuring food with your eyes...

Hi guys!  So I remember reading something about a deck of cards being 3oz? of protein.  I know it shouldn't be relied on 100% of the time, but just wondering if you guys have any other tips n tricks for eyeing portions when on the go.  Thanks!

My NUT says ask for an empty salad dressing container if you are in a restaurant - those are 2 oz.  I use that to make sure I get the right amount when I'm out.

I use the Ziplock small containers to pre-measure my meals.   To the top of the plastic lip is 1 cup (measure with a measuring spoon).  I pretty much eat from these now for everything because I know what my stomach holds depending on what the food is.  So while I started by measuring first then filling the container I can now just put directly into the container and know when to stop.  I have about a dozen of them and will pre-measure my breakfasts and lunches for my work week as needed.  

I recommend measuring until you are comfortable eye-balling your food but then every once in awhile going back and measuring again to check that you are still on track.  It sure helps when you are out at a restaurant if you know how much steak to cut off and push aside so you are eating the right portion :)