To learn about the different methods for placing symbols, see the Choosing a symbol placement method section in the Symbols Overview Help topic.

Use one of the provided symbol templates for making symbol files. These templates have been stripped of unnecessary background sheets and other data to make them much smaller than regular templates.

Do not embed symbols inside symbols. Using symbols embedded in symbols with Embed or Shared Embed insertion mode almost always results in longer processing time and larger file size with no additional benefits. Also, inserting a symbol that has an embedded symbol into a draft document as geometry results in a group object that contains an embedded symbol object, which also increases processing time and file size.

Do not place drawing views in symbol files. If you want to make a symbol of a drawing view, it is best to convert it to a 2D view first. That will break the link to the model and avoid associativity problems. 2D views are not associative to models.

Avoid the use of layers as a display control mechanism in your symbol.  Instead, put geometry into groups and use the show and hide group capability. This is especially true when the insertion mode is as Geometry. Because layer on/off states are not copied (all layers are copied as "on"), any layer name conflict will defer to the state of the layer in the main draft file, not the symbol.