if you are holding PRC passport, you can only apply for visitor's visa.

besides all the documentation mentioned in the application form, you 'd better show more evidence of returns.

if you have working contract, show them, and state clearly the consequences if you fail to go back to Singapore in time.

if you are holding scholarship, go to school registra's office to get approvel letter from the authority, in which you should state clearly the consequences of not returning.

and show all the documentation that you think can manifest that you have no intention to imigrate.

the possibility is the same for applying individually or through travel agencies.

if you are holding students pass, the possibility of getting the visa is very low. 7:3, in which 3 is those who get the visa.

if you are holding working contract, you have more possibilities to get the visa.

to get the visa, you must show all your evidence of return, as long as those are reasonable, and sound, i mean in the embassy's view, you will get the visa.

they are quite rational as least.

last but not the least, good luck