Presented review is an attempt to analyze progressive enhancement in performance of solar collectors in view of changes in design of collector components, changes and modifications in process parameters and advances in working fluid produced by addition of nano-particles in base fluid of water or oil. Observations based on contributions of many researcher's shows that design, process and working fluids have functional relationship among them which resulted in improved working efficiency. Optimization of these parameters will lead to highest thermal efficiency. The presented review is focused on synergistic approaches, processes, design criterions and advances in working fluids to achieve optimum thermal and exergy efficiency for solar collectors mainly flat plate solar collectors, evacuated tube collectors and concentrating collectors. Recent trends that has been witnessed as steadily upward growth, reveals that incorporation of modern working fluid along with phase changing materials embedded with nanoparticles and compatible design changes can produce optimized results. On the basis of comprehensive analytical investigation of published works by many researchers, valuable contributions from scientists and engineers it can be interpreted that design modification, suitable working fluids along with phase changing materials can further make solar collectors more versatile in terms of application in water heating, process heating, power generation and integration of these devices in buildings and agricultural works.