Time management is a common problem CFA candidates normally struggle with in the exams.
While doing tons of practice papers would help calm the nerves, one could also take a little bit of time to get to know and use the calculator better for some epic timesaving tips!
Her'e a list of a few lesser known functions that I used for my exams for the BA II Plus calculator. I hope it helps speed up your calculation process in the exams and reduce errors at the same time!
Recommended BA II plus calculator settings for CFA
A few introductory notes:
 Note the syntax. [ ] is for buttons, " " is for the (beige) words on top of the buttons. " " is only applicable when we use the [2ND] button for additional functions.
 Press [CEC] button twice to clear your calculator before moving to the next operation.
 Don't press the RESET function (i.e. [2ND] "RESET") unless you want to reset all your settings back to factory settings. If you accidentally did that, you would have to reconfigure your calculator settings as below.
[2ND] "FORMAT" [9] [ENTER]


[2ND] "P/Y" [1] [ENTER]


[2ND] "FORMAT"
[↑] [2ND] "SET" 

General tips
A few general tips here that applies to all levels, try them, and choose whichever works best for you. This section is not meant to be a comprehensive section about all the TVM and CF functions that you need to know for your exams, but rather a few tips that hopefully speeds up your calculation process whilst maintaining accuracy.
[ ( ] and [ ) ]


[→]


[CEC]


[2ND] "K"


[STO] [number/answer] [assigned number]
[RCL] [assigned number] 

[2ND] "ANS"


[2ND] "CLEAR TVM"


Statistics function  the hidden gold
While I'm not going to go into detail of how to use TVM or CF functions (you should know this anyway), I find that Statistics function is one of the relatively unknown functions that actually saves a ton of time especially for Quants or Portfolio Management topics. Basically any question that requires calculation of the standard deviation or mean from a data set.
Here's a sample data set: 20, 15, 5, 3, 8
Here's a sample data set: 20, 15, 5, 3, 8
[2ND] "STAT"
[2ND] "SET", repeat until you reach the "1V" setting [CEC] [2ND] "DATA" [2ND] "CLR WORK" [20] [ENTER] [↓] [↓] [15] [ENTER] [↓] [↓] [5] [ENTER] [↓] [↓] [3] [+] [ENTER] [↓] [↓] [8] [ENTER] [↓] [↓] [2ND] "STAT" [↓] as needed 
To setup your calculator to do single variable statistics, press [2ND] "STAT".
Toggle using [2ND] "SET" until you see 1V. The other 4 settings: LIN, PWR, EXP, Ln are for regression analyses which we won't be needing for CFA exams. Clear screen and let's input the data above. Enter the data setting, and always clear memory of previous entries before entering new data. Enter data into X01, X02, X03.... etc, and leave Y01, Y02, Y03... as default of 1. X represents data, whilst Y represents frequency of that data point. The screen would be showing "X01 0". Proceed to do the data entry for the 5 points, as per instructions on the left. Then, you enter into the Stats function to see "1V", which is the correct setting. By toggling with the [↓] button, you'll see the results: n=5, mean x̄=10.2, sample standard deviation S(x) = 7.12, population standard deviation = 6.34. A quick way to get the population mean and standard deviation! Source: 300 hours
