Here are some tips for fitting a tackler:
* Use a 24km disruptor. In a mass battle it is much easier to catch an enemy ship and get the wanted 2 killpoints with a long disruptor than with the short web scrambler. A twenty kilometers disruptor also means that you can sit on a gate and catch ships without much extra effort.
* Use MicroWarp Drives.
* Forget armor plates, use nanofiber structures.
* No damage modules. If you're not in an assault ship with T2 guns, the damage from a tackling frigate is little. Use nanofibers / overdrive, if nothing else comes to mind.
* Passive tank instead of active tank. Shield extenders are ideal for T1 frigates (and some interceptors), armor plates are not very desirable (very bad agility and MWD speed). If you decide to use plates, do not you use larger 200mm, if you use a shield booster you either die or run out of capacitor before the booster will do something significantly useful.
* Use Long-guns and Long-range ammunition. Long range in a tackling fitting means at least 10 + km to the default fire range. Damage is not what is expected from a tackler. Do not sacrifice holding the target as long as possible at a long range and survival for a better damage to the target. This is not a objective of a tackler.
* Make sure you have enough energy to make long (or frequent) warps. Use boosters. Train skills Warp drive operation and Energy management. Your aim should be for flights of more than 100 Au with no additional warps. This requires good skills (and not possible for all frigates), but warping to least 60 AU - is required.
* Use T2 modules, if you can fit them. If you are constantly shot down and spend ships as fast as a machine gun fires bullets, use cheap T1 mods, but still T2 ones are obviously better.
* Use the Rifter as a training tackling ship. No matter what your skill plan is, training for a Rifter with T1-T2 modules requires a week or maximum two. Why the Rifter? Because it has a great set of slots, a lot capacitor (for a frigate), it's cheap, fast and has sufficient CPU-PG for most tackling setups, it has a small signature. For the Rifterom long flights are not a problem. And to feel comfortable it is enough to hgave the skill Minmatar frigates trained to level 3.
Outlined above are the basics. Some variants of fleets or situations can throw out a particular rule from those above, but if it happens - the FC will announce it and will explain what tasks are required from a tackler, and in most cases will help to find the right fitting.