Based on my experiences, here are some quick tips to improve test release process continuously:

Tip #1) A release engineering team needs to be set up which will take care of the crucial tasks such as maintaining software releases/builds and Software Configuration Management (SCM) systems.

Tip #2) Project teams that solely abide by the process of Software Development Life Cycle (SDLC), Product Development Life Cycle (PDLC) and Software Testing Life Cycle (STLC) should be appreciated well. It is easy to define the processes but until it is followed by the people involved, defining the process holds no meaning.

Tip #3) Estimations for testing efforts should be prepared based on past experiences. Writing test cases is completely different from its execution. Software testers should understand the critical factors like what to test, when to test and the approach. Otherwise, the efforts involved are bound to go waste, even if extensive rounds of test cycles are executed.

Tip #4) If feasible, automating the testing phase using universally accepted testing tools can help because these tools can reduce efforts by 50% or even more. A well designed automation framework leads to improved quality of software and results in 100% quality.

Tip #5) Last but not the least, do not treat test release like just another job. It is no less than an art to make the lives of project stakeholders easy and more comfortable.