Converting Arduino Due 3.3V digital pin to 5V
This is a simple level shifter where speed is not important and current gain is not required. It requires only one resistor and a single TO-92 or SOT-23 (eg. 2N7002) transistor:



simulate this circuit &ndash; Schematic created using CircuitLab

As you can see, the rise time is a bit slow, and there is very little drive capability because of R1, and sink current is limited by the GPIO, but it will work into a CMOS input or similar.
For more stringent requirements, I recommend a voltage translator chip. You can do a parametric search at a distributor and find many kinds that can translate from one voltage to or from another.