The curation rewards time limit is now 7 days so you wont get anything if you vote after that. It was up 30 days in the past, but this has changed.

When you vote you get a share of what is added to the post after you vote so it is better to vote before other people if you want to make curation rewards. There is however a penalty if you vote in the first 30 minutes to how much you will receive but this doesn't apply to voting on your own posts, just to voting on other peoples posts.

Id say in your case if your posting just upvote your own posts immediately, it's probably the best option to start with.