The quick, easy and secure alternative to tying knots - use a crimper and appropriately sized sleeves to make the connections. Not in single-strand wire though, it'll slip. Guaranteed. The Haywire Twist is the only way to go in this material.
In cable or plastic-covered multi-strand wire you'll have to make crimped connections - there's no alternative.
Similarly in heavy mono, certainly above 150lb breaking strain, you'll have to resort to sleeves as the line is too inflexible for knots to be cinched up tight.
And if you haven't already got one, this Bluewater Rigging Kit will provide all you need to get started.
A standard use version is all youll need and wont cost a great deal. Personally though, I favour the slightly more expensive model that has a double-pivot arrangement like the one in the kit above, as this provides a better mechanical advantage and ensures that the sleeve is fully crimped up.
The cup-to-cup type, as shown on the left, is the best choice as you'll see a few lines down. Mine has four different size cups and accommodates sleeves up to 2.2mm diameter, which cater for mono lines from 40lb to 500lb, and multi-strand cable from 50lb to 900lb.
Take care when selecting which size sleeve to use the leader should fit snugly inside the sleeve but be capable of being easily drawn through it, prior to completing the connection. You cant use too small a sleeve the leader simply wont fit - but you can go too large. Then you will have to over-crimp the sleeve to get it to hold at all, resulting in some very unreliable connections.
There are three styles of sleeves in common use - Round Section, Oval Section and Figure-of-Eight, or Double-Barrelled Section. It's worth taking a look at each of these.
Round sleeves can only be compressed using a point-to-cup type of crimping tool. This plier-type tool has various cup shaped indentations on one jaw, and a matching series of rounded points on the other.
In use they squeeze the sleeve around the leader, but the contact made isnt uniform even less so if the leader is crossed inside the sleeve.
This type of sleeve results in unreliable connections and best avoided altogether in my opinion, apart from light load applications.
One such application is using a round sleeve (rather than the figure-of-eight knot shown in the sketch) on a daisy chain, where it keeps each of the teasers a set distance apart.
Cheap and quick to fit, this type is a firm favourite of commercial longliners, who use them by the bucketful.
A cup-to-cup crimping tool is used to compress oval sleeves.
This differs from the cup-to-point version in that both sets of indentations are concave, semi-circular cut-outs.

The snuggest possible fit is obtained, and the resulting connection is very secure.
These are also compressed using the cup-to-cup tool, but its vital that the sleeve is located correctly in the tool.
The wrong way
Its tempting to lay the sleeve in two adjacent cups on one jaw and then operate the tool.
This is wrong, and wont work.
The right way
Turn the sleeve through 90° so that it is located within a single cup in each jaw, and compress it through its longest axis.
Sleeves are usually produced in one of two materials aluminium or copper, but nickel and less frequently brass ones are sometimes seen. Use copper ones with cable and aluminium ones with mono. Why? Well...
Cable is made of stainles steel strands. Aluminium and stainless steel are at opposite ends of the galvanic table, and aluminium being at the least noble end will corrode galvanically when immersed in seawater, much like the sacrificial anode on the underside of a boat. Not a good idea to mix these two then.
Whilst copper sleeves can be used on mono, they are more likely to cut or damage the line than aluminium ones. And you don't want that. So then, aluminium sleeves for mono and copper sleeves for cable.
First select a double-barrelled aluminium sleeve of a suitable diameter, and decide whether or not you should reinforce the loop you intend to make.
If so and its not a bad idea slide a short piece of plastic rig tubing over the line before returning it through the other barrel from the opposite direction.
Alternatively, form a Flemish Eye.
If you meant to use the loop to connect to a hook or a swivel, then you should have threaded the line through the eye of the hardware before completing the loop. Hah!
For belt-and-braces security, leave - for the moment - a couple of inches or so (50mm) or so of the tag end projecting through the sleeve, and then:~
For example, the 1.3mm diameter sleeves I use are 7mm long, and the 2.2mm diameter ones 13mm long. The jaws of the crimping tool are 4mm wide. So for the smaller ones I crimp them once, leaving flared ends of around 1.5mm at either end.
For the larger ones, I crimp them twice, leaving similar flare ends and with a short un-crimped section in the middle of the sleeve.
Its really important that you dont crimp right to the end of the sleeve, as you'd be very likely to damage the line.
This is pretty much the same process as making one in mono, other than the tag end melting bit.
Remember to use a copper or brass sleeve - definitely not an aluminium one.
Its important that you don't leave an exposed tag end in cable, as it can cause quite nasty cuts if you have to handline your catch in.
Some anglers intentionally leave a longish tag end, then contain the very end in a second sleeve. Good idea!
If you like the idea of having the most popular sea fishing knots all together in one place for easy reference, this handy little pocket guide is just the thing.
It sets out in step-by-step instructions and nicely drawn sketches how to tie all the knots you'll ever be likely to need - 18 of them in all.
Being spiral bound it opens flat, leaving both hands free to tie the knot - and it's waterproof!
Connecting Hooks, Swivels and Lures to Single-Strand Wire Line
Forming a Stand-Off dropper Loop in Mono Line
Forming a Reinforced Loop in Mono Line
Connecting Mono Line Directly to Single-Strand Wire Line