Browsing through some of the languages here, I've noticed three major approaches or "styles" to constructing a language...

1) The cryptographers - This appears to be the most liberal form of conlanging. In its most basic form, the creator of the language simply replaces a "real-language" word with a new one, while more advanced forms tinker with grammatical elements such as word order and conjugation. Essentially, the resultant conlang is merely a "coded" form of the original language. This is not necessarily a negative approach, but without care it can lead to a language that is difficult to learn and understand due to a relative lack of consistent structure.

2) The phonologists - This is the form most encouraged by the opening template for new conlangs. Those who follow this pattern utilize professional linguistic standards to develop a language, almost from scratch. This can create various structures, but the heavy usage of technical terminology can also inhibit many readers from comprehending the language. It's one thing to say that a letter or character represents the ch sound like in the Scottish word loch, but quite another say it represents "the voiceless velar fricative."

Again, there's nothing necessarily wrong with either the cryptographic or phonological style. But one thing that both seem to forget is another element of structure underlying most languages: culture. Thus the third approach, which I personally favor...

3) The anthropological - In this style, the cultural backstory is as important to the structure of a conlang as the organization of sounds or the creation of grammatical rules. For example, in my own conlang of Kiitra, I have two terms for the concept of reconciliation; one is the word genkijem ("to mutually forgive"), and the other is the idiomatic phrase lobel frem inraluu/zraluu/airaluu ("to repair our/your/their door"). While the first neither requires nor reveals any cultural background, the second definitely does - a metaphor similar to Robert Frost's proverb that "good fences make good neighbors." The only shortcoming of a purely anthropological approach is that it demands the reader or user to learn and understand an intricate culture in order to understand the language.

Ultimately, a combination of all three approaches are what's needed. Even an anthropologist has to incorporate both a phonologist's understanding of syntax and semiotics, and the playful creativity of the cryptologist. But in the end, any conlang needs sufficient degrees of accessibility and vraisemblence to attract an audience.