AUD/USD has developed wave A of long term uptrend from 1.0390 to 1.1079 (colored coral in the chart). Now corrective wave B is developing. Within this wave there are A, B and C subwaves - colored red in the chart - with subwave C still developing from 1.1063.
The targets of the downmove are Fibonacci retracements of 1.0390-1.1079, and expansions off 1.1079-1.0910-1.1063, 1.1063-1.0923-1.1006.
Supports:
- 1.0653 = .618 retracement
- 1.0639 = super expanded objective point (SXOP)
- 1.0621 = SXOP
If the price reverses to the upside the immediate resistances will be Fibonacci retracements of 1.1063-1.0679, 1.1006-1.0679.
Resistances:
- 1.0804 = .382 ret
- 1.0826 = .382 ret
- 1.0842 = .50 ret
- 1.0871 = .50 ret
- 1.0881 = .618 ret
- 1.0916 = .618 ret

Overbought/Oversold
Assuming that the medium term trend is down it's preferable to try short positions when the Detrended Oscillator goes above the zero level (current prices) or gets into the overbought area (10-25 pips above the current prices).
Read more on how to apply Fibonacci studies to calculate price targets.