So you want a molecule that has a plane of symmetry and you want to make sure that molecule has chiral centers. ummmm spotting them there are shortcuts but I would definitely know how to check with R/S. When you're looking at Fischer projections you want a molecule that when you draw a horizontal line you see 2 symmetric images. Same for cyclic and linear....look for symmetry. There's a trick to the linear molecules: if you click and look at the linear molecule picture you see that the OH on the left sticks out in the front and the OH on the right sticks out in the back. However, if you rotate around the bond at C3, when OH is up you will see that it sticks out just like the one next to it. This is something to remember to help you spot meso compounds fast. but it's always good to check
There are two main ways, 1. The easy part....look for a molecule that has chiral carbons AND a plane of symmetry. 2. A trickier part....a molecule that " hides " the symmetry such as a Fischer. If this is the case,,,,,,simply do the R/S...if half the molecule is R...and half is S....AND the same groups are present.....you have a meso. There are a few questions on this that you will practice in DESTROYER.