1. 下一次/下次 (next time) 

Imagine the present time is the beginning of a list. When you go further down the list, the further into the future you will be at.  


2. 上一次/上次 (last time) 

Imagine you are currently in the middle of a list. When you look up the order on the list, the further you go up, the further you got back in the past.

3. 之後/以後/後 (after)

Don't think of '後' as 'back' but think of it as 'behind/ follow behind'. Imagine the present time is the start of a road. the rest of the road in front of you is the future which you follow. 

For Example: " 第二次世界大戰**後** " (follow WWII = **after** WWII) . 

"第二次世界大戰" was the reference point of a time line. Every thing that followed, would be the future of that point of reference.


4. 之前/以前/前 (before) 

'前' here doesn't mean 'forward'. It means 'previous'. As in '前男友' (ex-boyfriend), '前政府' (previous government). Therefore. '以前' means 'from the previous' = 'before'. 

*前(forward) can also mean 'future'. Imagine the present time is a line you stand on.  '向前看' (look forward) is the future. See similar terms like: 

- '前途' (road forward = future ahead) 

- '前景' (scene forward = future prospect)