Ice Cap thickening
The Arctic Ice cap can be thickened and restored by pumping sea water on to its surface using renewable power systems. This would be done in the colder winter months and over multiple years.
The ice thickening can either be done over large areas to maximise albedo and trap methane emissions or locally to create ice structures grounded onto the sea bed to prevent warmer waters from entering into the Arctic.
Due to the heat flow into the planet and the high levels of heat already stored in the upper layers of the ocean surface, then a full scale deployment of Marine Cloud Brightening is most likely to be a necessary predecessor before ice cap thickening efforts can become fully effective.
The concept of ice thickening is well established and was used as a cost effective method to provide platforms for subsea drilling in the 1970s, see here.