I think it depends on your artwork and what 'look and feel' you want
... some cards have titles or numbers woven into the artwork (not necessarily in a uniform top or bottom placement), others have borders or banners allowing for a uniform display of titles... Some decks use numbers (no titles), others have both, some have none ... I know, there are infinite choices
Like OnePotato said, planning (or at least thinking about) titles, is a good thing to consider while you are creating the artwork ... to avoid it becoming a stressful afterthought at the very end.
When working on my own deck, I allowed extra space at the bottom of the artwork for the titles, which I added 'on top'.
If you are thinking of adding borders, it is a really good idea to work out what your final print (card) size will be - with those measurements on hand it is ever so much easier to create borders that won't 'chop away' your precious artwork