Due to the sheer size and vastness of the Shi'Ar galaxy, the Shi'Ar have utilized some very advanced technology to create "Stargates" to help them fly from one place to another within Shiar space.
These stargates are heavily guarded so that they could not be used by enemies of the Shi'Ar and are dispersed through out the Shi'Ar galaxy at suitable junctions so that space travel time can be greatly reduced. Once a ship has entered into a star gate it will enter some form of hyperspace to emerge at the target Stargate a short while later. It is not known precisley how stargate navigation is achieved, however the stargates have pre-defined routes that will send a ship to a specific exit stargate. It is common knowledge amongst the Shi'Ar as to where in the known universe each stargate will take them to. Having said this, it is possible for a starship to alter the destination stargate they will be sent to but it requires some time to re-calibrate the gate to do this.
[as shown in Uncanny X-Men #200-201 when the Starjammers rescued the dying Xavier from Earth]
[Starjammer entering a stargate]
[Starjammer exiting a stargate]
Besides these large stargates for use by starships in outer space, the Shi'Ar have also adapted the technology to create portable stargates to transport people from one place to another. These can be used virtually anywhere, but need to be calibrated for an exit point. [first shown in Uncanny X-Men 105]