Well from what you have said here are some ideas to help you.

1. Let the players design their plot hooks. Give them some setting details, alignment/race restrictions with a clear idea of what unifies the party (political ambitions, a singular mutual organisation, all working at the same place etc.) The main thing is if the players design their own characters and you build the plot hooks around their backgrounds then they will feel more engaged.

2.Have an idea for a major plot but don't force it down the players throats. The plot doesn't have to be something the players have to follow in a clear set of events but should always be lurking in the background as they prepare to resolve it. It needn't be immediately obvious but could include any number of things (rigging an election, defeating a world ending evil that is being heralded by various signs, overthrowing a dictatorship, revenge against a mutual enemy)

3. Go into your sessions with plenty of ideas for side quests/daily events. If possible make these relate to the major plot (as mentioned in point 2) even if it is only slightly. If the players stumble into a quest as a result of their own actions as opposed to being told to go places constantly it doesn't feel like railroading.