I have a little trick I use when I am saving up gold or mana. I will reconfigure my base, and move the recourse I am not saving out. So if I am saving gold, I move all my mana vaults and mills outside of my base. This allows me to have a tighter constructed base, that allows me to have walls almost 4 rows deep all the way around. All heros, and enemy troops will focus on breaking through the walls. My towers, troops, and heros are all placed within the walls with the recourse buildings to strategically attach the enemy troops when they hit the first wall. My towers are able to pelt the heros before they reach the wall. I know a lot of people are using smurf accounts, but I find this to be a little more fun. Just watching wave after wave of attacks fail. Yes they get my mana, but my gold is safe. Or vise versa. I kind of get a kick out of seeing 10-15 failed attacks when I log back on. Seldom does anyone get the gold, but those who do deserve it, because they had to go all out for it.
smart. I go something like this. I only defend 1-2 buildings. If you are saving gold, 1 single vault at level 13 holds 350,000 gold. Two of thes holds 700,000 gold. Since all the gold fills up one valut at a time, you can focus totally on just defending those 2 vaults at all costs. Next to them put your other gold mines, so they also cannot be picked off. Now, suddenly, your opponent needs to (at the least) 35% you to even be in reach of touching them.
The goal is to force your raider to kill you as much as possible in order to reach your gold...as I see it.