Development of quantum technologies face unique challenges due to the fragile nature of quantum systems. A quantum system may be controlled by cooling down its environment so much, that there is no energy left to disrupt the fragile quantum system. At these temperatures, the quantum system is in the ground state. Superconducting circuits are one such quantum system. They are cooled to about 10 mK using a dilution refrigerator, which should ensure that they are in the ground state. However, this is not the case when it is investigated. This thesis focuses on three ways of improving the ability to keep superconducting circuits in the ground state by measuring and suppressing excited state populations. One advancement is the precise measurement of the excited state population or effective temperature. The chapter introduces a new method of measuring the effective temperature using correlations between consecutive measurements. This method relaxes previous requirements on the quantum system, expanding the types of systems that may be used. We also use neural-networks to improve the accuracy of single-shot measurements. This chapter introduces the use of a graphics processing unit for on-the-fly computing and classification of the state of the measured system. Being able to accurately measure the state of the system allows for corrections to be made to the system. Radiation from higher temperature stages of the refrigerator is one of the causes that superconducting circuits seem to have a higher effective temperature. The third chapter details the progress made towards an on-chip circulator to prevent such radiation from reaching the qubit. This would allow for smaller and integrated circuits. Here I also describe the process used to fabricate a device. These improvements can all help towards building a large scale quantum computer.