Caps and methods of usage thereof are provided. In certain aspects, a cap includes a block having a first and a second surface. The first surface can include a male or female connector, and the second surface can include a male or female connector configured to removably attach to a classroom instrument. The classroom instrument can be, for example, a glue stick, a highlighter, a marker, or a writing instrument. In some aspects, the cap can include a cover configured to removably couple to the block. The cover can include a first side and a second side opposite the first side. The first side can include a decorative object disposed thereon, and the second side can be configured to contact the first surface of the block when the cover is connected to the block.