Arpeggios are an essential feature in your playing. Many a times arpeggios are going to help you out during chord changes. To master arpeggios start with three string exercises. You can create your arpeggios. Choose the notes that sound meaningful and start picking(alternate picking). You can also pick it by selecting upstroke while going up and downstroke while going down. Do it slowly to a metronome for at least 1000 times to get the flow.