Macro photography options?

I'm new to the SLR segment. Just bought Nikon D5300. I have two lenses- Nikkor 18-55 kit (VR) and Tamron 16-300.

I'm looking for macro options. I want to take 3:1 macro shots. Now, clearly, I'm out of budget already. So, I can't buy a dedicated macro lens. I need a cheap alternative. I've been considering the following options:

** Raynox DCR 250 snap on
** Kenko extension tubes set
** Bellows
** Reverse mounting of my existing zoom lens
** Double mount

Now, I don't know the exact capabilities and limitations of these. I'm gathering information over internet only. So, it'd be very helpful if you help me choose. Also any other option is welcome too.

Your big problem here is aperture control, which rules out the bellows, and no front adapter is worth spit.

Your only real choice is the extension tubes. You're unlikely to retain autofocus, but you MUST be able to transmit your aperture setting from body to lens.

Kenko has nice extension tubes. However, I think you should sell your 18-55, seeing that you have another lens that completely overlaps your focal range. With the money you get from selling your 18-55, buy a cheap prime lens, perhaps the 50mm f1.8 AF-D (if you're tight on money, no autofocus) or the 50mm f1.8 AF-S, OR the 35mm F1.8 (my favourite for DX cameras).

With the Kenko tubes and a prime lens, (50mm/35mm), you should be set for macro photography.

EDIT: Reverse macro of your existing 18-55mm isn't a bad idea. At 18mm, reversed, you will get magnification levels of higher than 1:1. However, it is difficult to focus and dirt can get in if you don't have a mount. (a dead ant fell out of my 18-55!). But if you do get a good mount, pair it with a tripod and remote and you should be good to go! (this is "budget" option)

If you can't afford something good right now, then you can't afford to waste partial savings towards something good buying junk.

Reverse mount your lens. You could maybe pick up an old 28mm prime lens from a thrift store where the aperture ring also works thereby controlling depth of field better in manual.

More info:
http://photo.blogoverflow.com/2011/07/take-macro-shots-like-this-for-less-than-the-cost-of-a-pizza/

Take 1:1

Snap-on and screw-on have poor optical quality. Extension tubes are good enough. Bellows are cumbersome to use but viable. Reverse mounting won't work if your lens does not have an aperture ring. Double-mount?

Get the extension tubes and use with the 18-55mm.

Things to consider when seeking a macro alternative
Max magnification
Our macro alternatives were tested with a standard Canon EF-S 18-55mm kit lens. Bear in mind that different lenses will result in different maximum magnifications than those we achieved.

Increase light ¨
Macro add-ons can darken your exposures by several stops. To compensate, shoot in Av or Tv mode and increase your Exposure Compensation. Also use a reflector to bounce more light into your scene. A pop-up reflector can be quite cumbersome with small subjects, so try an A4 piece of card with silver foil attached to one side for a handheld reflector.

True macro ¨
A true macro image has a magnification ratio of at least 1:1. This means the object is recorded at full size on the sensor. However, some macro options can give you extra magnification, so a ratio of 4:1 means that an object that is 3mm in size will take up 12mm on your sensor!