There's a couple of things that will help drive up ABV:
Rouse the yeast. Do this just after fermentation begins to slow. Don't worry about oxidation as long you plan to keep it on the yeast for some time. The yeast will clean up any oxygen introduced into the wort through rousing.
Add additional sugar. Add to the primary once fermentation begins to slow. The yeast will become active again and dry things out further than where you started.
Increase the temperature of the primary. Once the primary fermentation is complete, there is no longer a concern of off flavors from fermenting too high, you can let it sit in a warmer location. This will increase the yeasts metabolic rate.
Lower mash temperature. If you mash in the high 140s to low 150s you will generally produce a more fermentable wort, which will lower FG.
Grain selection. Avoid cara/dextrine malt. They lower the fermentability of the wort. Replace with other malts to add color (chocolate in super small quantities or darker kilned malts in smaller amounts).
Yeast selection. Pick a yeast that dries things out. S-05 is very good for this. Nottingham is even better (but different, thinner results).