Hi
For the best performance from your devices, check that both Bluetooth and Wi-Fi are enabled on your iPhone (and keep them permanently enabled).
Also check that you have installed the latest versions of all apps (on your iPhone: App Store > Updates). To also automatically install updates for associated Apple Watch apps, enable Automatic App Install (on your iPhone, in the Watch app, go to: My Watch > General > App Install).
It may help to unpair and re-pair your watch. The Watch app on your iPhone takes a backup of your watch automatically when unpairing via the app. Choose to Restore from Backup during set up. Most data and settings will be restored, with some exceptions (eg Apple Pay cards, passcode):
Looking ahead, note that new features under watchOS 3 - the software update that is due for release this Autumn / Fall - include significantly faster loading of your favourite apps, including apps launching immediately with updated information.
More information:
http://www.apple.com/watchos-preview/