畅所欲为 do whatever one wants [likes]; do all that one wishes to do
畅所欲言 speak one's mind freely [without reticence]; air one's views freely; assert without any restraint; express one's opinions [views] freely; express oneself with zest and gusto; have one's say; say out one's say; say exactly as the mind dictates; speak freely [outright; without any inhibitions]; speak one's piece; speak out freely; speak straight from one's heart; state one's views unreservedly; talk to one's heart's content
从心所欲 have whatever one's heart desires; do as one pleases; free-wheeling