The centuries old Lenten traditions of prayer, fasting and almsgiving are prudent practices during Lent. They emphasize a balanced perspective on self-denial and penance and doing good for others. Somehow the idea took hold in the Church that you don't "give up" anything for Lent, you "do something good" for someone. I suppose one out of the three isn't bad, but why not do all three? There seems to be a recent return to penitential practices as we acknowledge their benefit and avoid excessive or overly scrupulous ones.
In the "do something for others" category, how about this: we all know someone who has stopped attending mass. Why not encourage them to go to church during Lent, perhaps invite them along with you. Just think of all the people who will attend mass on Easter day only, and perhaps not again until Christmas. The positive impact your invitation and encouragement can have might be the most important evangelization you ever do.
Think about it, pray about it, then invite someone to mass.