The 2013 quarter-finals finished bottom of Group C following a 2-1 defeat to Ghana on Tuesday.
Mandla Masango gave South Africa a first-half lead, only for John Boye and Andre Ayew to change the game with goals in the final 17 minutes.
South Africa also went ahead in their other two group games before losing 3-1 to Algeria and drawing 1-1 with Senegal.
And Mashaba, in his fourth spell in charge, knows he has a lot of hard work ahead.
"We need to go back to our basics of playing football, when to do things, how to do them, and where to do them," Mashaba told reporters.
"We need that ability to kill off a game, that is one of the things I am talking about when we say the basics."
Reflecing on the defeat, he added: "I think we gave it our best. We came here and scored a goal but we couldn't consolidate.
"In the first half we played very well. In the second half, in the first 10 minutes we started to sit back. We tried to push them out, made changes, but it didn't work out. "
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