How do you select what you need? Some times it can be difficult picking between what you want and what you don't want. One way is to isolate the layer an object is on. That is not always practical. For example, suppose you want to select a certain block in a file that has been inserted several times. You can isolate the layer it's on, but the blocks entities are on different layers, or the block was drawn on certain layers, but was inserted on a different layer!! (not always the best thing to do)
There are several options. You can create a selection query through the "FILTER" command. This command can be done by itself, or transparently (that means it can be used while the user is already in a command.) If the same selection criteria is used over and over again throughout a project or just in daily tasks, creating a filter might be a good idea. That way the steps don't have to be repeated every time.
To do this, start the FILTER command. (Just type in FILTER at the command prompt.) A window opens with many options. Give the filter a name (it's a good idea to name the filter according to the desired selection.) There are many search criteria to choose from, or simply select an item that meets the needed criteria. All searchable criteria from that object will be placed in the window. Remove any item that is not needed, otherwise, the filter will only be able to find that one item!!! Save it. Start a command (copy, move, delete, etc.), when prompted to select the items type in 'Filter. Make sure the apostrophe is there. This makes a command "transparent." Select the saved filter, click OK, and any item that meets your search filter will be selected. Of course, you actually have to do some selecting. If the item doesn't match the criteria you can't pick it!!!
What if you don't have a pre-saved filter? Just start the filter command transparently within your command and select the needed criteria.
Another way of using filters is with the "Quick Select." It works much the same way as the filter command, but you can't save your criteria. It too is transparent. The interface is a little more simple to work with so it is quicker. It doesn't provide all of the criteria options that filter does, but typically it will provide enough to get your work done.
Start a command, type in 'qselect. Again, the apostrophe makes it transparent. There will be options to choose from like, layer, color, block, type, etc. Select the item that best fits your needs. A second choice that narrows down the selection is available. Select it and presto your needed items are selected.
After using these filters a few times they will become second nature. There are several ways to invoke the quick select command. Play with it to find out which way works best for you.