Introduced in the Cisco IOS Release 12.2(15), Gateway Load Balancing Protocol (GLBP) is supported by Cisco 1700, 2600, 3620, 3631, 3640, 3660, 3725, 3745, 7100, 7200, 7400, 7500 series. GLBP is a Cisco proprietary protocol that attempts to overcome the limitations of existing redundant router protocols (HSRP, VRRP, …) by adding basic load balancing functionality.
GLBP [...]

As you see in the article “Implementing High Availability with HSRP“, it is quite simple configure Hot Standby Router Protocol.
Some cases require a custom configuration, using priority, track, preempt etc…and these are:

The standby preempt interface configuration command allows the router to become the active router when its priority is higher than all other HSRP-configured routers [...]

The Hot Standby Router Protocol (HSRP) is a Cisco proprietary first-hop redundancy protocol (FHRP) designed to allow for transparent fail-over of the first-hop IP router, and has been described in detail in RFC 2281.
HSRP provides high network availability by providing first-hop routing redundancy for IP hosts on Ethernet, Fiber Distributed Data Interface (FDDI), Bridge-Group Virtual [...]