Almost anything can be collected, but to promote collectibility of your products, you should release them in identifiable sets (Carey, 2008). Use names, symbols or colors to connect products. Even subtle additions like a numbering system can turn a mere range of products into a collection.

Self-identity is a primary motive for collecting (Smith et al., 2008), so creating distinction through scarcity (“I have this but you don’t”) is key to increasing consumer status.  Hold back or stop supply of certain items to create a secondary market. 

Create a community to foster social value of your collection. This provides social acceptance - one of the core reasons people collect (McIntosh and Schmeichel, 2004). Social also heightens resell value.

Release collectibles in waves over time (Bianchi, 1998). This will increase the overall enjoyment of the experience and increase the desire to collect. Never saturate the market with too many sets, variations within sets or too many limited editions (Hood, 2006). Overproduction will kill the magic and therefore consumers’ ongoing desire to collect. Don't make the pursuit too easy to achieve (Csikszentmihalyi, 1990), but also not so large a task as to be out of the reach of your audience (McIntosh and Schmeichel, 2004).