Basically, to remember the difference of greater than or less than, whichever the inequality sign is facing (the alligator mouth), that is the greater one. (The alligator wants to eat the bigger number. This is what I learned when I was younger.) I use to have trouble with that too.
Then, for graphing inequalities, a closed dot means greater/less than or equal to. A open dot just means greater or less than.
Also, when you have an inequality equation like -3x> 18, remember to switch the sign when dividing by a negative number.
Hope this helps!!