Custom fees between Canada and USA

What is best to do when goods are sold from Canada to USA and from USA to Canada to prevent custom fees. What about NAFTA agreement, rates, etc. Thanks for you advises.
I have heard some people write "gift" on the customs form. I do not know what the fines are to those who get caught in a lie. I paid a duty six months ago and just figured that is like paying sales tax. No big deal, probably a lot less than the penalty. I wish I knew how NAFTA worked also; and if there is a legal way to reduce or abate the duty??
Canada customs does not charge duty on US made electronic components. You will, however, have to pay the provincial and goods and services tax. The cheapest way for items coming from the States is via USPS. Canada Post charges Can$5 plus the applicable taxes. Items coming via UPS get charged brokage fees on top of the applicable taxes.
i bought a cd player from some geezer in canada and he put that it was worth $100.00 on it and there was no tax or anything---(can to us)
Thanks guys ! Turbodieselvw: How sure you are when you say that Canada does not charge duty on electronic components. Where can I check this information?
Martin - you might find something at the Revenue Canada & Customs website (not sure of web address). As Turbo indicated, you will have to pay the appropriate taxes and if shipped via USPS,Canada Post will charge you a $5 handling charge to collect the taxes. I have had a number of US made products shipped here to Alberta and have only paid the GST (the benefit of living here..) on all of the items. As indicated, avoid UPS as they have their "hidden" brokerage charge that you only find out about when the package is delivered.
I can only reiterate what Rgd and Turbodieselvw have said: Canada does not charge customs fees or duty in electronics imported from the U.S. (in accordance with NAFTA), but, like every other transaction, you have to pay sales tax. Until last year, you only had to pay GST, but now PST is also charged. I avoid UPS because the brokerage fee is a minimum of CDN$33 and it rises as a percentage of the item's value. Also, I've had several damaged items via UPS but, so far, none via USPS airmail. I have no information on Canada to U.S. shipments
Martinparel, I have purchased power amp, pre-amps, and cables that are made in the US and have never been charged duty. I have also purchased tubes sent via USPS and have not been charged any duty on them (so far). FedEx (air) factors the brokerage fees into their shipping charges, unlike UPS. I have shipped an amp to the US using FedEx and am assuming that there were no additional charges levied as the purchaser didn't mention anything about about that issue to me. I also personally feel that USPS provides much better service than UPS. Dr_joe is correct with regards to NAFTA and customs charges - no charges for US made electronics. However, again, the provincial taxes and GST apply.
Thanks everybody. It is really appreciated. Turbodieselvw: Thank you very much.
I cannot comment on non-NAFTA import fees into Canada, but under the Harmonized Tariff Schedule of the US for 2001, your typical high end stuff is covered under section 8518.40.10 (audio amplification equipment). For Canada, if the equipment entirely originates there (i.e. principally manufactured there), it is duty free under NAFTA. Otherwise the duty rate is typically 4.9% of the declared value. Declaration and payment of duty is done informally for personal items under $2000. Check your local US Customs office for further details.