Stop my pot splashing me
Put in your food slowly, as you already discovered. If they are largish pieces, e.g. whole potatoes, you just need the patience for it. If you have a bowl of something small like beans, use a ladle to take scoops out of the bowl and lower it into the water. 
In addition to 1, use a larger pot with higher sides, but don't fill it. A little bit of splash will happen, but it will not reach you or spill over your stove. 


Also, I don't know what you mean by "boil something", but I suspect you may be blanching vegetables. If this is the case, I find it best to use a large sieve analogously to a fryer basket (boil in the sieve), else you can never get the whole amount in and out quickly enough to not undercook some pieces and overcook others. 

For something almost "flowing" like rice or couscous, you can also find something spouted to measure them in, and slowly spread the food over the water from a low height. Basically, you really need the "slow" part, you cannot just throw everything and not get splashed.