Once we have the scale in our hands, with our picking accuracy happening, we jam with the scale. We start this process whether we are ‘good at it’ or not. The 1000th time will be better than any attempts in the single digits.
First, tinker with the tones of the scale, without audio or too much thinking.
Next, use some audio. Audio can be a recorded song that you like that is in the key of Em or G. Any song which use G, Em, C, D [very common] is a candidate. Put on the tune, and solo the whole time, even figuring out vocal lines.
Start the track and use the scale to improvise. Sing to yourself. Find what you sing.
E minor 12 bar: (4 beats each) : Em Em Em Em | Am Am Em Em | Bm Am Em Bm