So you might not think of an altar as being a 'tool'. But really, it kinda is. It's a very sacred place for your magickal workings, for holding your other tools, for showing your "Pagan Pride". In some pagan paths the altar is an outdoor structure, usually made of stone. For those still in the 'broomcloset', it can be a nightstand or a space on the mantel that doesn't outwardly look pagan. For me, I have a nice little cupboard type of thing. It has a drawer that I use to hold candles, oils and incense. Then there's a door on it with a couple of shelves inside that I use to store the bigger items. This is the one 'tool' that I personally feel is a must. I know I said that no tool is absolutely necessary and that you can get by without them. This one is the only exception. If you do not have the space to have a dedicated altar, you can use your kitchen table or your coffee table or an end table. Just be sure to cleanse it before you use it and, if possible, use an altar cloth. I have a couple of places in my apartment that can be considered 'altars'. The mantel over my fireplace holds a goddess figure (my husband calls her 'the silver naked lady') and my house guardians, the nightstand in my bedroom holds a framed picture of a goddess with a candle, and then there's my actual altar. The top of my altar doesn't look very pagan, to me anyway. It only has two white candles, a very small crystal ball, a couple of seashells (for water), a couple of stones (for earth) a feather and an incense holder (for air) and my athame (for fire). I think the most pagan looking thing on it is the altar tile (not a necessity but I like it), it's just a small soap stone with the triple moon on it, there's a pentacle inside the full moon. But it's in my bedroom and really, no one else needs to be in there. LOL
If you have older children that are interested in The Craft, they can have their own little altar spaces in their room (no candles, obviously, unless they're like teenagers or something). My daughter dedicated a shelf on her bookcase. My son dedicated a shelf on his. Simple stuff like stones, feathers, sea shells, unlit cone incense, wickless candles, can all be used on a child's altar to represent the elements and not look too pagany.
The altar is a tool that you can have fun with as a family decorating for the Sabbats. Make it a family project. just make sure the little ones know that it is a sacred thing and not a toy to be played with.