Monster Grip (spray on) is great, have used it on the nose of several boards, very grippy and have not have to reapply re wearing out.

From my experience, there are 3 solutions:

[1] spray on paint. I use monster paint, which I think is great, as it is durable, grippy, and very clear. Other brands may work, just to be sure to test that they are actually clear when dry, and stay clear even after some time in the sun. They make little grains, a bit like sand, sugar... You can get some rash if you fall on it.

[2] peel-on traction. I only used versatraction, they work via "micro holes" that act as suction cups when wet, but are slippery when dry. Very cool as they do not cling to the bag. The material also provides some protection to the board against paddle hits. They are very smooth to the touch and do not chafe skin. The drawback is that they give a feeling of "slipperynesss", as your feet do not gain full traction till you apply your weight on them, so you must get used to it. But it great for moving around, like crossteping, and adjusing your feet. Also, they are not clear when dry which can be ugly depending on your tastes. Good point is that they are easy to peel off, for reselling if the new owner do not like it

[3] wax. Messy (less messy with modern brands), but the scent of the wax in the morning brings memories of the good old sessions so much...