Paperclip
Paperclips are not something we usually think of as a "tool." Yet, they are sturdy and small, providing many uses to the LEGO builder. Without altering its form, a paperclip is a great instrument in pulling up flat or thin tiles off of larger base plates. Hold the paperclip between your thumb and forefinger to get a grip on it and slide the rounded tip under the tile corner. This gives you leverage to loosen the tile from the base plate. Exercise caution when using a paperclip to prevent the metal from scratching the plastic blocks.
Brick Separator
The brick separator is a tool made by LEGO to help pull apart bricks that are locked together. This tool is designed for grasping small plate components that you can't get your fingers around. Without this tool, you will find yourself breaking fingernails trying to slide them between the pieces, using teeth to pry them apart or abandoning the pieces altogether. This tool works on its own or with another brick separator to pull items apart. You can also use the tool as a brick for unique designs and sculptures.
Poker
Many LEGO designs use axle-like rods to hold various components of designs together. Trying to get these items out is nearly impossible unless you have a tool to push it through. Build this tool by using round four-peg pieces with a center cutout for a rod. Stack your pieces long enough for you to hold the tool with ease. Place the rod in the center. Your finished product may resemble a LEGO screwdriver. Use it to get into hard to reach areas or press components down firmly. Most LEGO builders will not realize how valuable this tool is until they use one.
Graph Paper
LEGO creators designing custom portraits and sculptures use scaled graph paper. LEGO graph paper meets the size calibrations of LEGO components, allowing you to create your designs in true scale dimensions. This makes it easy to count out the number of stud lengths you need for any part of your creation. Create precise designs of items with the graph paper or build creations directly on top of it. LEGO graph paper can be found through online retailers that focus on customized LEGO crafts.