Kanji Trick?

Reading kanji characters seems a bit frustrating as each has multiple readings.

Do you use the prefix (or suffix) reading if the character(s) that come after (or before) it hiragana?

For example, if the character 月 has hiragana before it, is that an idicator that the 月 character would be read as one of its suffix readings げつ / がつ ?

Thank you c:

Can you name an example of when there would be a hiragana in front of it?

All I can think of is kanji: 毎月（まいつき）、来月（らいげつ）、今月（こんげつ）、先月（せんげつ）、九月（くがつ）、一ヶ月（いっかげつ）、生年月日（せいねんがっぴ）。Meanings respectively: every month, next month, this month, last month, September, one month, birthdate.

From my experience, it is usually getsu, unless it is referring to a date (exact month, in the word for birthdate). All the months are gatsu.

Yes. Also, "gatsu" is only used in the names of months, example, March 三月　(sangatsu), November 十一月　(juuichigatsu)

For the other readings, it is used in words, Japanese names, adverbs, particularly adverbs that use "getsu" or "tsuki"

So in summary, gatsu for month names and the others for the rest.

Example... solar eclipse 日蝕　(nisshoku), lunar eclipse 月蝕　(gesshoku) (getsu is used, getsu + shoku = gesshoku)

full moon 満月　(mangetsu)

Hope this helps. ^^