A good starting point is to just take a day to note the things that draw your attention. Sometimes it's not actually an object but a pattern of movement or light and shadow that can be a motif for an idea. Texture is often an inspiration, good for abstracts but also learning to imitate textures can develop your realist painting skills. Looking at other artists' work can be inspirational, but if you like someone else's style or subject, do your best to put your own imprint on it.
Music can be inspirational...not just something soothing to listen to while you work, but have you tried to express the feelings you get from certain songs? Books can be inspirational also...we all make pictures in our heads of the characters and places we read about.
Lastly, if you want to get the inspiration flowing, set aside some play time for your art. There's a lot of ways to do that...I sculpt with polymer clay but every once in awhile I sit down and play with making jewelry components just to try the different techniques involved. It's fun and non-taxing. When painting just grab a word or phrase out of the air and sit down and play with the idea. If you just are at an impasse and can't think of a thing, then maybe it's time to sit down and see what colors you can mix by playing around...keep notes so you can repeat it when wanted.
And lastly, you can just doodle. Sometimes your unconscious mind knows where it wants to go, so just let it wander for awhile, you might be surprised to find that, if you just let go, your path will find you.