See this thread. Measure twice, cut once. Hopefully you have a rotary paper trimmer or, more common but less preferable, a 24"x24" guillotine paper cutter. Cut one sheet at a time, until you get familiar with it. Then cut 3 sheets at a time, max. Also if the blade is dull, and almost all are, pull the blade toward the anvil as how push down, other wise you can just crinkle the sheets. Keep the tissue paper on the gel until you put it in its frame. Ask the person in charge where and how to label each piece. If not using the full sheet, cut the end away from the label or Roscolux printing first; this way you don't end up with a large partial sheet unlabeled. Be sure to keep the sheets square on the table, parallel with the grid lines. Often there's tape denoting 6.25", 7.5" and 10". Make sure you know what the frame sizes are. Ask about a white china marker if you don't see one. (I've used black sharpie, but never in the center, only in the corner.) I prefer to label cuts in the lower right hand corner, then frame it, and place the brad (paper fastener) in the upper left hand corner. I only use two brads if it's an outdoor show. Use a drywall screw, any length, to pre-punch the hole for the brad, as most brads aren't rigid enough to punch the hole. Know and use the standard prefixes: R for Roscolux, L for Lee, G for GAM, and AP for Apollo. R119 is way different from L119. If adding frost and color in the same frame, ask whether they want the frost on the inside or outside, some LDs/MEs are picky about things like that. If using R104, R113, L228, or other Brushed Silk, ask them which way they want the grain running. If cutting any rectangles (cyclights) plan the cuts in advance, as one way might get one more cut out of a sheet. Ask if they want to save the scraps. If the "Color Cut List" calls for two 7.5"x7.5", go ahead and cut 3 or 4, and keep them as spares, especially with frosts. Depending on how organized where you are working is, you may be pulling color from a file before figuring what you need to cut. Verify that what you pull is the correct color, and is not burned or faded. ALWAYS label every piece of color, cut or uncut, even the scraps! I like to label every full sheet in each of the four corners, which I find makes it easier when filing. See this chart for standard sizes.