Guides:Masonry Skill Tips
Masonry
Building houses is said to be good skill gain, but you can't even do that until you hit 30 Masonry, and at 75 skill I personally gain no skill using my WoA/CoC trowel even after putting up 10 walls.
The best way to gain skill is to simply improve grindstones and other items that fall under the Stone cutting sub-category another way is constructing low stone walls. Many towns don't allow statue spamming, as this contributes to lag, while grindstones can fit in chests and be carried easily, which is why they are preferred.
The bonus to this is that you will also have higher %s on making stone bricks and stone slabs. Improving forges and ovens is also great skill gain, but does add a large amount of clutter to an area.
Another decent way to skill up Masonry is to improve an iron fence with stone bricks. At 27/28/29 Masonry you can around .031/.029/.027 skill respectively per improvement with it taking about 30 seconds per improvement at full stamina.