Luckily for the CubeSat builder, this stage of the mission is beyond your control!
Ensure your CubeSat meets the CubeSat specifications
Send it to your integrator (e.g. Cal Poly)
Wait for launch
If possible, send team to launch site in order to observe & learn
Launches are often delayed. You should be prepared for this, with procedures to (re-)charge batteries while in storage, verify functionality, even update software fix bugs.
Launch is risky! Rocket may explode! E.g. Russia 2006.