Lex Parsimoniae, the 'law of parsimony' is the most compact expression of Occam's razor, which in simple terms means 'don't over-complicate'. This is extremely important guidance for poets, as it's very tempting to explain, where one should ideally leave matters to the reader's imagination. I concur with the late Robert Graves that poetic wonder should be implied, not described. He proffered no reason for this, but I think it's because the specifics of any given reader's sense of wonder necessarily depend to a great extent on their individual prior experience. Excessively descriptive writing pre-empts and bypasses the power of the reader's personal imaginative response to your poem.

A golden rule, therefore, is treat adjectives and adverbs with extreme caution. We all know the sea is blue (or green, or restless), so unless its fundamentally necessary (e.g. it's vital for the message that the moon happens to seem unusually large tonight), let description be implied by analogy or inference rather than stated baldly. But if you absolutely must explain about that moon, do try not to use the word 'big'.

Sadly, achieving description by inference and analogy is much harder than by bald exposition. It requires access to a vast fond of both imagery and vocabulary that can only be acquired painlessly by extensive observant participation in life, plus deep and wide immersion in all the arts (not just literature) and an active right brain – a cluster of attributes that has rightly been called 'experience'. Looking stuff up when stuck for analogy or inference is ineffectual – the equivalent of using a thesaurus rather than an etymological dictionary when you're lost for an individual word. And this is all the more the case in this 'online' age, where dictionaries, let alone thesauri, concentrate almost exclusively on the most topical (and typically mundane) 'equivalents'.

As an example of an intuition based on my personal fond of experience, in a poem about collapse of inspiration I needed to express both collapse of the capacity itself and that collapse being a burden to endure. The form of the poem was already defined and extremely compact so there was very little latitude. But I spontaneously remembered from a long time back an expression from Hamlet's famous 'To be or not to be' soliloquy:

'Who would fardels bear'  1

The word 'Fardel' seemed an interesting candidate for describing the burden of failure, and then to my delight I found from the Oxford dictionary that a fardel can be a quarter part of something as well as a burden. So I wrote:

My verse declines from bad to worse:

My thought is flat; my words are terse.

'Tis but the fardel of my art

[...]

Via that single word, both the loss of talent as burden, and that the talent has been reduced to a quarter of what it was, have been indicated.

Without that fortuitous act of memory, it would have been practically impossible to convey both concepts simultaneously and concisely while retaining the structure of the stanza intact. So this is quite a good example of Lex Parsimoniae in action. But I'm sure I wouldn't have come up with that optimum word by merely sitting down and thinking (left brain) from scratch in the absence of the Hamlet soliloquy being imprinted on my mind from way back.

It may be considered (and often is) that not many readers would understand words such as fardel, so they shouldn't be used (the 'accessibility' argument), but if that argument is taken to its logical conclusion we're reduced to writing in Basic English with its mere 850 primarily pragmatic words 2 or, ultimately, in Newspeak.3 But this either forces the use of often abominable and complex circumlocutions when attempting to express ideas of any subtlety, or results in loss of meaning itself.

I hold that it's better (within reason) 4 to find and use the most appropriate word from the language in which you're primarily writing 5 – a word that succinctly expresses the desired meaning – rather than restrict ourselves to what we assume (probably incorrectly in any case) to be a universal vocabulary. If the reader is interested enough it's always possible for them to pick up a dictionary (or at worst to do a Google search), but if they're not, the poem is probably not for them anyway.

 [1] Hamlet, Act 3 Scene 1, soliloquy line 21, clause 2.

 [2] in which you can read or write 'verse' but not 'poetry'.

 [3] although I've been told that a poem has been written entirely in emojis, thereby completely sidestepping analogy, inference and subtlety of expression (or even specific meaning). But I suppose it does represent the ultimate in parsimony.

 [4] I recently encountered a poem written, according to the author, using only those English words that are derived from Old Norse. It was not easy to read, and as it didn't adhere to Old Norse poetic form I still (in odd moments) wonder why it was written like that.

 [5] nevertheless, a couple of lines (at the most) in a foreign language can sometimes be useful, for example a famous foreign language quotation as an epigraph that provides context, provided a translation is offered on the same page. I've done this myself on occasion. But I'd certainly never quote extensive passages in languages the reader is unlikely to know – that's just common courtesy.