There are some general rules.
(1) If the whole has only one part, like, 天，then start and finish all the top strokes, followed by the left then right strokes.
(2) If it has two distinct parts, (most likely a "radical character" on the left), like, 侈, always finish the radical first and here you usually also start from the top most stroke. As for the main right hand character, you also start from the top and work your way down.
So, generally, whether it's radical or "main" character, it's:-
left or top stroke first, then go down.
NEVER, right first, bottom up!!!
(3) There are words with radicals on the right, like, 副. Here you do the left main character first.
(4) There are words with radicals at the bottom, like, 思. Do the top main character first.
(5) There are words with radicals on top, like, 茶， (well, by now you should know what to do first)
(6) Words with a "square", like, 国, all the "internal stuff", in this case, 玉，must be finished first before you "close off" the square with the final stroke -- the bottom horizontal line of the square.
After a while, a certain pattern should emerge as you get the hang of it.
Finally, you need to learn as many radicals as you can, (about 200 odd of them; you don't need to learn them all; maybe 20-30 to start off) There is just no way around it. The radicals will get you to use the dictionary, without which no language could be learned.
Also the radicals give you clues as to which "family" in the scheme of things the word belongs; like things that have something to do with water, like "sea", 海，will have the water radical on the left side. But some radicals are not so obvious, like, 岛, ("Dǎo", island); where is the radical?
Finally, practice makes perfect, 熟能生巧, (Shú néng shēng qiǎo)