We've touched on this issues in a couple of posts so I thought I'd put a bit of emphasis into this here for the less experienced anglers. One post I see quite often on fishing websites is people seeking advice on how to tie a particular type of knot. There are a myriad of different types of knots that we can use.
I would like to emphasise that knots are one of the key fundamentals in fishing and is arguably magnified beyond any other type of fishing when you get into heavy jigging and popping. If there are any fault in your knots, this type of fishing will find it out due to the heavy drags used.
That is why it is an imperative to learn a couple of reliable knots and learn how to tie them properly. You must be able to have faith in your knots because as Neil stated in another thread, the last thing you want to be worrying about when you are fighting a fish is the reliability of your knots. It is much better to be able to tie a couple of knots really well and be really practised at it than to be able to tie a myriad of knots of very average quality.
My personal view is that learning two key knots will see you through most popping and jigging applications. One is the bimimi double and the other is the albright. A bimimi double can provide you with the fundamental knot for both popping and jigging. For popping, this can be attached to a twisted leader by way of a catspaw (very simple) and for jigging, to a single strand of heavy mono by way of an albright.
If you can tie both of these knots really well, you're in good shape! Bimimis can appear nightmarish and you feel initially that you need an extra pair of hands to tie them. I encourage you to persevere as it will become second nature and it is actually not a difficult knot to tie once you have had enough practice. Believe me, if I can get good at it, anyone can!!
On a secondary basis, it is useful to be able to tie a knot like a midknot or FG for popping purposes. This knot comprises a single strand of braid to a single strand of mono leader and if well tied, is fine enough to be able to pass through the guides of a rod comfortably when casting. of course if you prefer, you could learnt his knot and use it in preference to a twisted leader. MY personal preference is still a twisted leader but there are many excellent fishos out there who swear by the midknot or FG knot.
Finally - test your knots. Tie them to trees, to fence posts etc but test them to breaking point. Whatever you do, don't leave your testing to the fish!! Learn to trust your knots!!