Just this lovely afternoon, this happened in the heavily-camped system of LXQ2-T. I don't mind being wrong, and I don't mind people making mistakes. But people who are so ignorant of rather basic warp mechanics need to be taught a thing or two. For the good of humanity. For Mother Russia. For SCIENCE.
Without further ado, I present to you, in no small part thanks to Gargantoi of Against ALL Anomalies: How To Make Pings!
BUT FIRST: WHY?
It's elementary. In Null-sec especially, you often do not want to warp directly to a gate or station. What if there's a gang waiting on that gate for you? Then they could jump in with you and then you'd be in trouble. Worse, what if there's a drag bubble just behind that gate (much like the one I was using to lure baddies into my Sabre)? Then you're stuck down Shit Creek, my friend. All kinds of things can go wrong. Maybe you want a safe passage to the gate, already knowing there's a static bubble behind it. Or maybe you just want to keep eyes on the gate for your fleet. There are many reasons for having pings, and pretty much no reason to not have or use them.
ON-GRID GATE PINGS
The most basic ping spot is made by burning (a MWD-fit frigate of any kind works great for this) at least 150km, preferably further, away from the gate in any direction except in the path of other gates/celestials/stations/etc. Once you're at the intended spot, open up your EVE Menu [\], go to 'People and Places' and then in the 'Places' tab click 'Add Location.' Give it a name and SAVE. Then, whenever you right-click in that system, you can approach or warp to that exact spot whenever you want.
The idea is that, when you warp from a gate to this ping (instead of directly to another gate), you will avoid landing in any bubbles and be able to assess what might be camping at the gate. Up and down work great, but better yet (as these spots are common and leave you prone to enemies who have the same pings) try a ping up or down and to the side not facing the star. You're much less likely to have enemies with the same or similar ping.
OFF-GRID GATE PINGS
While on-grid gate pings are nice, if you're not in a cloaked ship, you will still expose your presence to any enemies at the gate. If in the same way you made your on-grid ping, you go 'the distance' and burn over 1000 km from the gate, then save that location, warp off, and warp back, you'll notice that the gate is no longer on grid with you. That means, although you'll show up on D-Scan, you won't be immediately visible to a gate camp. Meanwhile, by using a limited-range D-Scan, you can tell what is waiting for you on that gate. It's a useful ping for FCs to gather a fleet and quickly swoop down on an aggressed and unknowing enemy.
So now you know that you can use the 'Add Location' tool while on a grid - but did you know that you can also use it while in-warp? Yes! Create your own custom safe spot between two celestials, or even better, between two previously saved safe spots, by making a ping in-warp. These pings are great for hiding in a system if there's nowhere to dock or no safe gates. There is a somewhat unorthodox method of finding somebody at an in-warp ping by 'closing in' on it with D-Scan, but most of the time, you'll be impossible to find or catch without Combat Scanner Probes. The best defense is to warp between older safe spots and constantly save new safe spots in a system so that you won't be on any one grid long enough to get scanned down.
0KM STATION PING
Have you ever safely landed on a station and then realized you're actually 2500m off that station? Has there ever been a fleet waiting where you landed? Is this where the bad man touched you? You should've had a station ping. Navigate anywhere along the edge of a station - preferably as far from the undock as possible, since this is commonly where you'll find bubbles - and make sure the station shows up at 0 meters on your overview. Then bookmark this spot. You'll have to manually select 'Dock' when you land on grid, but you won't land out of docking range any longer.
Being camped in a station sucks. But if there's no bubbles to keep you in, there's no reason why you can't hit warp if your intended location is directly in front of you. Use your MWD-fit frigate to burn straight out of the station undock. Look behind you to make sure you're aligned, as closely as possible, to the center of the undock, since stations will always spit you out at a random but limited angle. Burn out at least 200km from the undock (since the undock is usually located behind the docking range of the station) and then Add Location. Better yet, make an undock point off-grid. Make a lot of undock points and catch your enemies at their instas! Now we're having fun!
TO BEAT A DEAD HORSE
If you're ever in a tight spot, such as on a roam in uncharted terrain with no pings, try using planets and moons to get indirect warp-ins on gates. Most gates have at least one celestial body within scan range, which allows you to tell if it's being camped. Make sure your D-Scan is modified to pick up bubbles and scanner probes so that you can tell when somebody's waiting for you or looking for you. And, if all else fails, just make a safe spot and wait. It takes a little time, but it could save you a lot of ISK/tears.