There has been a tremendous growth in the deployment of IEEE 802.11 (a/b/g/n) wireless local area networks (WLANs) in recent years. This growth is due to the flexibility, low cost, simplicity, and user mobility offered by the technology. Such networks are being deployed widely in homes, offices, schools, shops, hotels, warehouses, factories, and almost anywhere that people live and work. Despite the potential benefits of WLANs, one of the challenges faced by network researchers and engineers of WLANs is to increase capacity (per user) and quality of service (QoS) of a typical WLAN with a medium-to-large number of users. While there are many factors influencing the performance of WLAN, wireless medium access control (MAC) protocol is found to have the most significant. This is because MAC protocol is the main element that determines the efficiency of the sharing of the limited wireless channel bandwidth since it coordinates data transmissions on the network. In this talk the presenter will highlight the key factors influencing WLAN performance. Various methods/strategies of improving WLAN performance will be discussed. These methods include designing a better MAC protocol by modifying the existing ones, cross-layer design optimisation, ways of reducing transmission overheads, and send more data (payload) under good channel conditions. WLAN design guidelines for optimum system design and deployment will also be discussed. Empirical results will be presented to support discussion. This talk is suitable for a general audience.