I'm working out the grammar of my pictographic conlang "Pikto". It's very preliminary, but the basic idea is to keep the number of pictographs to a reasonable minimum. I'm hoping 400 to 500 unique pictographs will cover a large lexicon by using compounds.

The basics, from my website:

 Capitol letters in the literal translation indicate symbols used for their phonetic value to further specify a previous symbol, with a phonetic hint, as in "flower DF" for "daffodil", or "bird K" for "crow". The hint letters are standardized, with the shortest hints for the most common words. Thus "bird R" might be "robin", whereas "bird RV" might be "raven". The symbol for water might mean "water", or it might mean some generic liquid, especially when modified with a phonetic hint as in "water P", or "flame water P", which might stand for "petrol" or "gasoline". There will be one alphabetical symbol for each of the 26 letters of the Roman alphabet.

Most verbs will be indicated with one of very few verbs followed by a noun, adjective, or gerund. Thus "play" would be "do game", "sing" would be "make song", and "sleep" would be "do sleeping". When no tense marker symbol is present the verb is assumed to be in the present tense, or in the established tense of the discourse. Thus, in a story which begins "Once upon a time", unmarked verbs are assumed to be in the past. Tense markers include "will", for actions soon to take place, "did", for actions already completed, "begin" for actions beginning to take place in the present ("He is starting to run."), and "doing" for actions begun in the past but still going on.

When an adjectives follows the word it modifies it is taken to be an ordinary adjective. When the adjective precedes the word, it is taken to be compounded with the word to change that word's fundamental meaning. For example, "man small" means "a man who is small" while, "small man" means "boy". Thus "small cat small" would be interpreted to mean "small kitten", where "small cat" = "kitten". The only exception is that when an adjective modifies a proper name it precedes the "namer dot": "little (dot) edward" rather than "(dot) edward little". When the adjective is considered to be part of the name, as in Robin Hood's sidekick Little John, it would be written "(dot) little john". "John" would be written phonetically as "JN" or "JON" depending whether it was clear from the context that the name is "John" rather than "Jan", "Joan", or "June". Later references to "John" in the same context will simply be written as "J".

Many adverbs are translated as "intensely" or "unintensely" to indicate an intensification or de-intensification of the natural action of the verb. Thus "run intensely" means "run quickly", "sleep intensely" means "sleep soundly", and "fall unintensely" means "fall gently".

Reduplication of an adjective intensifies the adjective. Thus "small small" means "tiny", and "big big" means "huge". Reduplication of a verb indicates repetition of the action, as in "run run" for "run again". 

My web page, under construction, gives translations for 21 sentence so far, as pictographs (fragz.ttf font required) and as Roman alphabet glosses.

The lexicon so far contains about 70 or 75 words and pictographs.