Virginia has so many ticks that the ticks have ticks.
Permanone, however, does a good job of killing them (sometimes at once but other times after 30 minutes) or making them so woozy that they forget they are supposed to burrow into you. What you want is for the tick not to bite you.
The effectiveness of this product, I have found, depends on how old the can is. Cans several years old still work but not as well. That conclusion is based on a couple of hundred cans.
DEET will work too, but it stinks to high heaven, unlike Permanone which has virtually no scent (also marketed as Permethrin and Duranon.)
In the old days people used coal oil or even sulphur on their socks, pant legs, etc.
Leaving a bit of the broken off head in your skin might not expose you to Lyme disease, Rocky Mtn. Spotted Fever, and various other rotten illnesses, but it will definitely increase the chances of the bite getting infected. Trust me on this! Please, hehehehe! Leaving a source of alien bacteria under your skin in proximity to capillaries is never a good idea.
I now use special tweezers that come with a magnifying glass to make sure you have gotten every last bit of the head out.
An interesting tactic for getting the tick to back out is to take a Q Tip, dunk it in sticky soap, and rub the tick counter-clockwise. It doesn't work, but it is an interesting idea.
Chiggers (red bugs) are not a source of serious illness however they may drive you to suicide or mass murder, both of which are serious.
A solution of one part bleach to two parts water will stop the itching. MSG diluted in water will too. Nicotine from spit-on tobacco will too. A baking soda concoction helps, as do commercial products like After-Bite.
Most of that stuff will help with skeeter bites too.
Then there's Poison Ivy...